Iran 'flouting' nuclear rules: U.S.

U.S. Secretary of State Hillary Clinton accused Iran on Monday of "flouting the rules," and called for a strong international response to Tehran's alleged development of a nuclear weapons program.

Clinton was speaking at the start of a month-long conference reviewing the Nuclear Non-Proliferation Treaty at the United Nations in New York City.

Iran's actions have "placed the future of the non-proliferation regime in jeopardy," she said. Clinton proposed that the treaty be strengthened by introducing "automatic penalties" for noncompliance, rather than depending on such drawn-out council diplomacy.

Earlier in the day, Iran's President Mahmoud Ahmadinejad rejected such allegations, saying Washington has offered not "a single credible proof."

Because of suspicions Iranian uranium enrichment is designed to produce bombs, the U.S. is negotiating with other UN Security Council nations to impose a fourth round of economic sanctions against Iran.

Pentagon releases warhead number

The Pentagon said the U.S. maintains 5,113 nuclear warheads in its stockpile and "several thousand" more retired nukes that await dismantling.

The announcement coincided with Clinton's speech and marked the first time the Pentagon has officially disclosed the number. The U.S. has previously regarded such details as top secret.

A senior defence official, speaking on condition of anonymity, said the size of the stockpile represents a 75 per cent reduction since 1989.

In his speech to a delegation of 189 nations, Ahmadinejad denounced the Obama administration's refusal to rule out the use of U.S. nuclear weapons.

"Regrettably, the government of the United States has not only used nuclear weapons, but also continues to threaten to use such weapons against other countries, including Iran," Ahmadinejad said.

He referred to the new U.S. Nuclear Posture Review's provision retaining an option to use U.S. atomic arms against countries not in compliance with the non-proliferation pact, a charge Washington lays against Iran.

Ahmadinejad also invited U.S. President Barack Obama to join a "humane movement" that would set a timetable for abolishing all atomic arms, weapons he called "disgusting and shameful."

Walked out

As Ahmadinejad spoke, the U.S. delegation, of working-level staff, walked out of the General Assembly hall, joined by several European delegations, including the French and British.

Foreign Affairs Minister Lawrence Cannon also boycotted the speech, saying Ahmadinejad's latest diatribe about the West amounted to little more than a "publicity stunt."

Ahmadinejad is the only head of state participating in the session and as expected he set the stage for a showdown about the long-running confrontation over Iran's uranium enrichment program.

Earlier, UN Secretary General Ban Ki-moon, opened the conference by directly challenging  Tehran.

"The onus is on Iran to clarify the doubts and concerns about its program," he told the delegates from 189 nations. 

He called on the Tehran government "to fully comply with Security Council resolutions" demanding that it halt enrichment, which Washington and others contend is meant to produce the nuclear fuel for bombs in violation of Iran's treaty obligations.

The treaty is regarded as the world's single most important pact on nuclear arms, credited with preventing their proliferation to dozens of nations since it entered into force in 1970.

It was a grand global bargain. Nations without nuclear weapons committed not to acquire them, those with them committed to move toward their elimination, and all endorsed everyone's right to develop peaceful nuclear energy.

The 189 treaty members gather every five years to discuss new approaches to problems, by agreeing, for example, that the International Atomic Energy Agency, the UN nuclear inspection agency, should be strengthened.

The only countries that are not treaty members are India, Pakistan, North Korea, all of which have nuclear arsenals or weapons programs, and Israel, which has an unacknowledged nuclear arsenal.

But the Nuclear Nonproliferation Treaty conference cannot easily "name and shame" an alleged treaty violator, such as Iran, since as a member state its delegation would block consensus.

In the first concrete step associated with the 2010 meeting, Indonesia announced last week it would ratify the test-ban treaty.

Obama has pledged to push for U.S. ratification of the pact, which was rejected by the Republican majority in the U.S. Senate in 1999.