Iranian President Mahmoud Ahmadinejad rejected allegations Monday that his country is developing nuclear weapons, citing "not a single credible proof."
Speaking to a United Nations conference on nuclear disarmament, Ahmadinejad condemned the continued possession of nuclear weapons by the United States and others. The monthlong conference convened Monday to review the Nuclear Nonproliferation Treaty.
Ahmadinejad said such atomic weapons are an encouragement to other countries to develop similar arsenals and called for a timetable for elimination of nuclear arms worldwide.
"The sole purpose of nuclear weapons is to annihilate all human beings and destroy the environment," Ahmadinejad said. "The nuclear bomb is a fire against humanity rather than weapon for defense."
"Its possession is disgusting and shameful," the Iranian leader said and "even more shameful is the threat to use such weapons." He excoriated the United States for being the country that developed nuclear weapons - saying the U.S. brought "the world to the brink of a nuclear arms race" - and the only country ever to use one.
Ahmadinejad criticized the "imbalance" in the nonproliferation treaty that allows nuclear-armed nations to maintain and even expand their stockpiles while scrutinizing other countries efforts to use nuclear energy peacefully.
U.N. Secretary-General Ban Ki-moon, opening the conference Monday directly challenged Tehran.
"The onus is on Iran to clarify the doubts and concerns about its program," the U.N. chief 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 NPT obligations.
"We are here not simply to avoid nuclear nightmare but to build a safer world for all," Ban said. "We need more examples of what can be achieved, not more excuses for why it is not possible."
Ahmadinejad, the only head of state participating in the session, was scheduled to speak later Monday morning.
Ahmadinejad's presence at the summit will test the Obama Administration's call for the world to coalesce against Iran's alleged expansion of its nuclear programs said CBS News Foreign Affairs Analyst Pamela Falk.
"Diplomats are expecting a marked contrast to the atmosphere of success after Obama concluded Washington nuclear summit last month and expressed confidence that the U.N. Security Council would rally around a new round of tough sanctions against Iran." Falk said.
Departing Tehran on Sunday, the Iranian leader made clear he would assail U.S.-led efforts to impose a new round of U.N. sanctions on his country. "Under the pretext of prevention of nuclear weapons proliferation, they impose heavy pressures on independent countries," Ahmadinejad complained to reporters.
He is also expected to counter with a denunciation of the United States and other nuclear-armed nations for their slow movement toward disarmament. "The atomic bomb has become a tool for bullying, domination and expansionism," he said Sunday.
U.S. Secretary of State Hillary Rodham Clinton, following Ahmadinejad to the U.N. stage later Monday, suggested over the weekend he was coming to New York "to divert attention and confuse the issue."
"We're not going to permit Iran to try to change the story from their failure to comply" with the NPT, she said on Sunday's "Meet the Press" on NBC.
While delegates assess the state of the NPT in U.N. conference halls, American and European diplomats will be working elsewhere to reach agreement with the sometimes reluctant China and Russia on a fourth round of U.N. Security Council economic penalties to impose on Iran.
Although Ahmadinejad's presence meant the first-day agenda was dominated by the Iran issue, it was only the beginning of a four-week diplomatic marathon meant to produce a consensus final document pointing toward ways to better achieve the NPT's goals of checking the spread of nuclear weapons, while working toward reducing and eventually eliminating them.
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 U.N. 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 NPT conference cannot easily "name and shame" an alleged treaty violator, such as Iran, since as a member state its delegation would block consensus.
At three of seven past conferences, delegates failed to produce a declaration, including in 2005, at a time when the U.S. administration, under President George W. Bush, was unenthusiastic about arms control talks.
President Barack Obama has steered the U.S. back onto a negotiating track, including with a new U.S.-Russian agreement to reduce their thousands of long-range nuclear arms. Despite that, Libran N. Cabactulan, the Philippine diplomat who is president of this 2010 NPT conference, said he finds the No. 1 goal of many treaty nations is to press the NPT nuclear powers - also including Britain, France and China - to move more rapidly toward disarmament.
In his opening remarks, the U.N.'s Ban listed "real gains for disarmament" as his first "benchmark for success."
To that end, the Nonaligned Movement of 118 developing nations has submitted to the conference a detailed "plan of action" for moving toward global nuclear disarmament by 2030. One its earliest steps is full ratification and entry into force of the 1996 treaty banning all nuclear tests.
In the first concrete step associated with this 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.