Iranian President Mahmoud Ahmadinejad kicked off the Nuclear Non-Proliferation Treaty (NPT) Review Conference with a lengthy diatribe against the United States and other Western powers who seek to sanction his country for its controversial nuclear program.

Mr. Ahmadinejad spoke for more than half an hour, giving what has become something of his trademark - a speech criticizing the United States, Israel and invoking God - and sending the U.S., British and French delegations walking out of the hall in protest.

He said the possession of nuclear bombs is not a source of pride, but is "disgusting and shameful."

"And even more shameful is the threat to use or to use such weapons, which is not even comparable to any crime committed throughout history," said President Ahmadinejad.

He criticized the United States for being the first nation to produce and use a nuclear bomb during World War II, saying it is one of the most hated countries in history.

And he accused Israel, which is widely believed to possess nuclear weapons but denies it, of stockpiling hundreds of nuclear warheads and receiving assistance for its nuclear program from the United States and its allies.

But despite his anti-nuclear weapons rhetoric, it is Mr. Ahmadinejad's government that is under a cloud of international suspicion for what many states believe is a covert program to produce atomic weapons. A possible fourth round of sanctions against Iran for failing to stop enriching uranium is being negotiated among major powers at the United Nations.

U.N. Secretary-General Ban Ki-moon encouraged President Ahmadinejad to "engage constructively" and comply fully with existing U.N. Security Council resolutions and cooperate with the International Atomic Energy Agency.

"Let us be clear: the onus is on Iran to clarify the doubts and concerns about its program," said Ban Ki-moon.

He urged the Islamic Republic to accept a nuclear fuel supply proposal from the IAEA that has been on the table for many months, saying that would be an important confidence-building measure.

Mr. Ahmadinejad replied to Mr. Ban in his opening remarks, saying Iran had accepted the fuel exchange deal.

"Well I would like to tell you and inform him as well, that we accepted that from the start," he said. "And I would like to announce that for us it is an accepted deal. Therefore, we have now thrown the ball in the court of those who should accept our proposal and embark on cooperation with us."

But in fact, Iran has not sent any firm reply to the international community and has sought to change the terms of the original proposal.

Later Monday, U.S. Secretary of State Hillary Clinton will address the review conference.

Conferences to review the operation of the NPT have been held every five years since the treaty went into effect in 1970, becoming the main legal barrier to the spread of nuclear arms. Delegates from the 189 countries belonging to the treaty will discuss compliance with its three pillars - nuclear disarmament, nuclear non-proliferation and peaceful uses of nuclear energy.

The month-long review conference will also likely focus on Iran's non-compliance with U.N. Security Council resolutions and IAEA safeguards, North Korea's withdrawal from the treaty in 2003 and its subsequent two nuclear tests, and the possible implementation of a 1995 resolution on establishing a nuclear-weapons-free zone in the Middle East.

The White House said Monday that Iranian President Mahmoud Ahmadinejad's harsh criticisms of the United States, other Western powers, and Israel at a conference reviewing the Nuclear Non-Proliferation Treaty, or NPT, demonstrate Tehran's increasing isolation as it faces international pressure over its own nuclear ambitions.

At a White House press briefing, Spokesman Robert Gibbs called the Iranian president's remarks "predictable" in that the Tehran government continues to fail to speak about nonproliferation obligations that itself refuses to live up to.

American, British and French officials "rightly" walked out, said Gibbs, as the Iranian leader make a series of "wild accusations."

"Those that are involved in the NPT conference, that are living up to the obligations, would have wanted to hear the Iranians discuss living up to their obligations," said Robert Gibbs. "I think them not doing that again shows how further isolated they are from the world community. And we continue to make progress on sanctions at a multilateral level, even as we look at ways that we can do so within our own government."

The United States, Gibbs said, continues to work with other U.N. Security Council members, moving forward on developing a new sanctions resolution, but he offered no new details on this process.

At the end of a nuclear security summit he hosted in Washington last month, President Barack Obama said he knew negotiations could be difficult, but that he would push as hard as he could to ensure that a resolution contains strong sanctions with "consequences for Iran."

In his address at the NPT conference, the Iranian leader attacked the United States and Israel, saying the production, stockpiling of nuclear weapons or threats to use them is "for people characterized by a lack of consistent logic and behavior."

Responding to President Ahmadinejad, U.S. Secretary of State Hillary Clinton told the nonproliferation conference in New York that Iran has defied the U.N. Security Council and the International Atomic Energy Agency and placed the Nonproliferation Treaty in jeopardy.

Against the background of the Iranian president's attacks on Israel at the New York conference that the White House made a point on Monday of reiterating the strong U.S. commitment to Israel's security.

White House Press Secretary Gibbs told reporters that President Obama, during a 20 minute telephone conversation with Israeli Prime Minister Benjamin Netanyahu, reaffirmed his "unshakeable" commitment to Israel's security.

Severe storms and flooding in three southern U.S. states have killed at least 15 people.

Heavy rains hit the states of Tennessee, Mississippi and Kentucky, causing flooding that stranded residents, blocked roads and left thousands of people without power.

Downtown Nashville (Tennessee), a popular area for tourists, has been evacuated. Cumberland River, which runs through the city, is expected to crest Monday.

Some information for this report was provided by AP and Reuters.

New York City Police disarmed a bomb inside a sport utility vehicle in the city's busy theater district on Saturday night, avoiding what officials say could have been a "very deadly event." Law enforcement officials are looking through hours of video surveillance tapes and examining other evidence to find the person responsible for what authorities say could have been an act of terrorism.

Law enforcement officials in New York are looking for a white male in his 40s who might be connected with a failed bomb attempt in the city's busy Times Square district.

New York City Police Commissioner Ray Kelly said, "Clearly it was the intent of whoever did this to cause mayhem to create casualties. This is just a sober reminder that New York is clearly a target of people who want to come here and do us harm."

During a press conference Sunday, Kelly said that video footage recorded a suspicious man changing his shirt near the vehicle shortly after it apparently was parked in Times Square. He said investigators are interviewing a tourist who believes he might have photographed the suspect.

Law enforcement officials say they found several containers of an unknown substance as well as three propane tanks, fireworks, two gasoline containers, and two clocks with batteries inside the vehicle.

Police quickly evacuated thousands of people from the area and closed off nearby streets while they disarmed the bomb.

New York City Mayor Michael Bloomberg said the "amateurish-looking car bomb" could have had serious consequences. "We avoided what could've been a very deadly event; certainly could've exploded and had a pretty big fire and a decent amount of explosive impact," he said.

The car bomb was discovered when a T-shirt vendor spotted smoke coming from the unoccupied vehicle and alerted police.

U.S. Homeland Security Secretary Janet Napolitano says the attempt to blow up explosive devices in one of the busiest districts of Manhattan, "certainly looked" like "it was intended" to be an act of terrorism. "We're taking it very seriously. It was parked in an area with a lot of traffic. It's too soon to tell who was responsible or what groups were responsible. So every possible examination of the device and forensics is being done," she said.

Times Square draws millions of tourists to its theaters and restaurants each year. The Department of Homeland Security did not raise the nation's terrorism threat level after the incident.

Authorities in New York City are viewing security camera footage and examining other evidence to determine who may have tried to set off a car bomb in the Times Square entertainment district.

Police evacuated thousands of tourists and theater-goers from Times Square Saturday night, after a T-shirt vendor noticed a suspicious vehicle and alerted officers.

Mayor Michael Bloomberg said the green Nissan Pathfinder sport utility vehicle contained three propane tanks, fireworks, two gasoline containers, and two clocks with batteries. He said the device looked "amateurish," but could have caused a "very deadly event" had it exploded.

A police spokesman, Paul Browne, says the bomb appeared to have started to detonate, but malfunctioned.

Bomb experts carefully removed the vehicle, and police reopened Times Square after several hours.

Bloomberg said authorities do not know who planted the bomb or why. U.S. Homeland Security Secretary Janet Napolitano said officials are treating the incident as though it could have been an act of terrorism.

She said investigators are following leads that include fingerprints and possible video of the car earlier on Saturday evening.

Times Square is one of New York's main attractions, with theaters and restaurants that draw millions of tourists throughout the year.

The U.S. Department of Homeland Security did not raise the national threat level after the incident.

Some information for this report was provided by AP, AFP and Reuters.

Iranian President Mahmoud Ahmadinejad is on his way to New York City to take part in a conference on the Nuclear Non-Proliferation Treaty.

Mr. Ahmadinejad is due to address delegates Monday on the first day of the month-long conference at U.N. headquarters. He is expected to defend Iran's right to enrich uranium, and to propose changes to the treaty.

Before leaving Tehran for New York, Mr. Ahmadinejad criticized the production and stockpiling of nuclear weapons.

Iran is a signatory to the Nuclear Non-Proliferation Treaty, which is designed to check the spread of atomic weapons worldwide.

However, the United States accuses Iran of secretly working to produce a nuclear weapon. The U.S. and its allies are seeking a fourth set of U.N. sanctions to pressure Iran to stop enriching uranium.

Iran says its enrichment program is for peaceful purposes.

U.S. Secretary of State Hillary Clinton is also scheduled to address the conference on Monday.

The review conference of states that are party to the Nuclear Non-Proliferation Treaty has been held every five years since the treaty went into effect in 1970.

Chinese have come out to get a first look at Shanghai's multi-million dollar World Expo after it opened its doors to the public on Saturday. Lines outside some of the more popular pavilions were extremely long, and there were occasional angry exchanges about line cutting. Most visitors, however, say they were impressed with the pavilions they were able to see.

World Expo organizers say that by mid-day Sunday nearly 400,000 people have already come out to visit the site and its more than 200 pavilions.

Expo organizers say some of the more popular pavilions such as the Swiss and French pavilion had more than 7000 people, on average, waiting in line to get a glimpse inside.

Buses were packed in many cases and sometimes a little pushing and shoving was required to get off at stops. But on a whole - aside from areas outside of the popular pavilions - there was plenty of room to wonder around or find a place to sit and rest in the shade.

The massive five kilometer site straddles Shanghai's Huangpu River and expo buses and ferries help visitors get from one side of the site to the other.

One 25-year-old software developer whose family name is Wang says he was impressed with what he saw in the Future Pavilion - one of the five theme pavilions at the World Expo.

Wang says that after seeing the exhibit he felt full of hope for the future. He says that there were many things in the exhibit that you do not usually see. Wang says the ideas put forth in the exhibit were really great, such as low-carbon economy and the many ideas about construction.

Mr. Zhang, a 21-year-old university student says he waited three hours to get into Britain's Seed Cathedral pavilion - a massive porcupine-like structure that encourages visitors to reflect on the connection the role of nature and city life.

Zhang says by noon on Saturday, he had only visited the Swiss and British pavilion.

Zhang says the British pavilion was awe-inspiring and that each of the thousands of crystalline rods that make up the structure have a seed at their end inside the pavilion. He says the light that comes streaming into the pavilion is impressive.

Mr. Lu and Mrs. Fan, a young couple who brought their nine-year old daughter to the expo disagree slightly about how long they had to wait. What is clear is that is was not short.

Fan says the wait was three hours and that the lines were incredibly long. Lu says three and half.

The couple, who live in Hangzhou, a city about two hours southwest of Shanghai, say they will have more opportunities in the future to come back and see more of the expo.

Lu says that overall he thinks the expo is well organized. He says there may have been too many people on the first day, and because of that lines were a bit long.

Events on Saturday continued well into the evening, with people still lining up at midnight to visit pavilions.

Expo organizers say more than 200,000 people visited the site on Saturday. Before the event wraps up in late October organizers expect that more than 70 million will come to visit and that the large majority of visitors will be Chinese.

Many visitors came prepared carrying foldable stools and umbrellas to beat the heat from the sun.

Mr. Wei, a 35-year-old cosmetics salesman from Anhui says he and his mother and brother started out early in the morning and made it into several sites. He says he was enjoying the science and technology aspects of some of China's pavilions and the South Korea pavilion. But after more than half a day of walking only had one thought.

Wei says he is tired, adding that there is really no way to see everything in one day. He too, plans to return again.

China says it has spent more than $4 billion on the World Expo, double what it spent on the 2008 Beijing Olympics. It is the most expensive Expo ever and local media reports put its overall cost, including upgrades to the Shanghai's infrastructure at more than $40 billion.