United Nations Secretary-General Antonio Guterres addresses the United Nations Permanent Forum on Indigenous Issues in New York on April 20. UNTV via AP.

BY EDITH M. LEDERER | THE ASSOCIATED PRESS

UNITED NATIONS - The United States and Iran clashed over Tehran's nuclear program as a review of the treaty meant to prevent the spread of atomic weapons got underway Monday at the United Nations, a confrontation almost certain to be repeated during the monthlong meeting.

At issue was the election of Iran as one of 34 vice presidents of the conference, where 191 parties to the Nuclear Nonproliferation Treaty are reviewing its implementation as they have done every five years since it took effect in 1970.

Iran was a candidate of what has been dubbed the "nonaligned movement," made up of 121 mainly developing countries.

Tensions over Tehran's nuclear program escalated ahead of the Iran war, with President Donald Trump vowing to ensure the country cannot build an atomic weapon. Iran has enriched uranium to near weapons-grade levels, but Tehran insists its program is only for civilian purposes.

The meeting began as Iran offered to reopen the Strait if Hormuz if the U.S. lifted its blockade of Iranian shipping and ended the war, while delaying talks about the nuclear program.

Iran is a party to the Nuclear Nonproliferation Treaty, which requires the country to cooperate with the U.N. nuclear agency.

But Iran has not given inspectors from the International Atomic Energy Agency access to nuclear sites that were bombed by the U.S. last June.

Christopher Yeaw, U.S. assistant secretary of state for arms control and nonproliferation, said that while there may be differing views about Iran's ultimate intent and how to address its program, Iran has shown "contempt" for its commitments under the treaty.

"Rather than choosing to use this review conference to defend the integrity of the NPT and call Iran to account, we instead elect Iran a vice president," Yeaw said.

"It is beyond shameful and an embarrassment to the credibility of this conference."

The United States was backed by Australia and the United Arab Emirates. The United Kingdom, France and Germany - parties to the 2015 nuclear deal to curb Iran's nuclear program that Trump pulled the U.S. from in 2018 - also expressed "concern."

Iran's ambassador to the U.N. in Vienna, Reza Najafi, called the U.S. allegations "baseless and politically motivated," declaring its opposition to the U.S. as a vice president of the review conference.

He said the United States was the only country to use nuclear weapons and accused it of expanding its nuclear arsenal in violation of the treaty and obstructing progress toward a Middle East free of nuclear weapons by supporting Israel.

Equally alarming, Najafi said, are the U.S. and Israeli attacks twice in less than a year on Iran's "peaceful nuclear facilities," which he called "a grave violation of international law and a direct assault on the integrity of the global nonproliferation" regime.

Also Monday, Iranian Foreign Minister Abbas Araghchi met with Russian President Vladimir Putin, Russian state news agency Tass said.

Russia broadly has stayed out of the latest conflict even as it's been floated as a possibility to take in Iran's highly enriched uranium.