US Secretary of State John Kerry addresses the Opening Meeting of the 2015 Review Conference of the Parties to the Treaty on the Non-Proliferation of Nuclear Weapons (NPT) at United Nations headquarters in New York, April 27, 2015. [Photo/Agencies]

Iran criticizes nuclear armed states

In a tentative deal reached between Iran and the six powers earlier this month in Lausanne, Tehran - which denies seeking nuclear weapons - agreed to curb sensitive nuclear work for at least a decade in exchange for ending sanctions that have crippled its economy.

Diplomats need to iron out details about the timing of sanctions relief, the future of Iran's atomic research and development program, the exact nature of International Atomic Energy Agency monitoring, and what kind of uranium stockpiles Tehran will be allowed to keep under any final accord.

Another issue that remains unresolved is Iran's past nuclear work that could have been related to weapons research. IAEA chief Yukiya Amano reiterated that he still could not confirm that Tehran's nuclear activities are entirely peaceful.

Amano also expressed hope that Iran would sign on to a more intrusive IAEA inspection regime called the "Additional Protocol," which the agency created after revelations about Iraq's clandestine atom bomb program in the 1990s.

"Implementation by Iran of the additional protocol would enable the agency to provide credible assurance about the absence of undeclared nuclear material and activities in the country," Amano said.

After the latest round ended without a breakthrough last week in Vienna, Iran and the six powers are expected to resume talks soon.

Sanctions are proving to be a key hurdle. Iran's Supreme Leader Ayatollah Ali Khamenei has said all sanctions, including the most severe restrictions on the energy and financial sectors, should be lifted the moment a deal is signed. But Western officials say this is not what Tehran agreed to in Lausanne.

At the NPT meeting earlier on Monday, Zarif spoke on behalf of the 120-nation Non-Aligned Movement. He demanded the five nuclear weapon states scrap any plans to modernize or extend the life of their atomic arsenals, while branding Israel a threat to the region due to its presumed nuclear stockpile.

"We call upon the nuclear-weapon states to immediately cease their plans to further invest in modernizing and extending the life span of their nuclear weapons and related facilities," Zarif said.

Israel, which neither admits nor denies having atomic weapons, is not an NPT signatory. An Israeli official dismissed the Iranian criticism.

Kerry spoke of Washington's "unequivocal" commitment to disarmament, though he admitted that more needed to be done by the United States and Russia.

"Despite significant reductions, the United States and Russia still possess more than 90 percent of the world's nuclear weapons," Kerry said.

He also said that the United States would accelerate the dismantling of thousands of retired nuclear warheads by 20 percent, and urged Moscow to take up a US proposal of further reducing nuclear weapons permitted under the new START treaty by an additional third.