Russia dampened hopes for a deal to rein in Iran's nuclear program, telling Tehran on Monday that it must first freeze domestic uranium enrichment. U.S. and German officials questioned Iran's commitment to addressing international concerns.
A report by the U.N. atomic watchdog agency said Iran appears determined to expand uranium enrichment, which can be a key step in producing nuclear warheads. The report also said a lack of Iranian cooperation has kept U.N. experts from establishing whether Iran's past clandestine nuclear activities were focused on making arms.
Iranian President Mahmoud Ahmadinejad, meanwhile, called American and Russian nuclear arsenals a threat to the Middle East and called for them to dismantle their atomic weapons, although there was no indication he was making the demand part of Iran's negotiating position.
The White House expressed doubt Monday that a Russian-Iranian deal would ease concerns that Iran's program is a cover for work to build atomic weapons, citing the indications that Tehran intends to continue uranium enrichment on its home soil.
Washington is supporting the Kremlin's effort, as long as the final deal results in all enrichment activities take place outside Iran and all spent nuclear reactor fuel is returned to Russia.
"We'll have to see what the details of any agreement are," White House spokesman Scott McClellan said. "Given their history, you can understand why we remain skeptical."
The developments came a day after Iran and Russia announced an agreement in principle for setting up a joint program to conduct Iranian uranium enrichment work on Russian soil, which would allow closer international monitoring.
But no details were settled, and Russian Foreign Minister Sergey Lavrov said Monday that the plan was contingent on Tehran ending enrichment activities inside Iran — something the Iranians have refused to do.
"Among other components of these efforts, there must be a moratorium on enriching uranium inside Iran until specialists from the International Atomic Energy Agency have clarified all issues concerning the Iranian nuclear program that emerged in the past," Lavrov told reporters.
Negotiations on the proposal were scheduled to resume in Moscow on Tuesday, the RIA Novosti news agency reported, citing an unidentified official in the Russian negotiating team.
The Iranians insist their program has only the peaceful purpose of developing technology to produce enriched uranium fuel to power nuclear reactors for generating electricity.
Germany's foreign minister, Frank-Walter Steinmeier, accused Iran of using the talks with Russia to try to divide the international community.
"Iran does not really have a new strategy" to defuse the crisis, Steinmeier told reporters after he was briefed on the Russian-Iran negotiations. "They still want to drive a wedge into the international community, but this will not succeed."
Lavrov stressed that the talks had not ended and would continue until the IAEA's board meets March 6 to discuss Iran.
The board voted early this month to report Iran to the U.N. Security Council, but the council is waiting for the report and the outcome of the board meeting before considering any action, such as imposing economic and political sanctions.
The delay was insisted on by two of the council's veto-wielding members, Russia and China, both of which have strong economic and political ties to Tehran.
Japan, which is a strong U.S. ally but also buys much of its oil from Iran, is keen to play a role in resolving the standoff. Japanese Foreign Minister Taro Aso urged his visiting Iranian counterpart Monday to respond "wisely and positively" to Russia's overture, his ministry said.
Aso stressed to Manouchehr Mottaki that Iran needs to realize other countries have strong suspicions about the Iranian nuclear program, much of which was kept secret from U.N. inspectors for years.
"Iran has lost the trust of the international community, and I hope to urge Mr. Mottaki to gain a better understanding of the international situation," Aso told Parliament.
The U.N. atomic agency's report on problems in the investigation of Iran's program was likely to add to those suspicions.
Iran's president did not mention the negotiations with Russia during a quick visit to Kuwait on Monday, but nuclear weapons came up in a meeting with journalists.
Asked about calls from the United States, Kuwait and other Arab states for the Middle East to be kept free of nuclear arms, Ahmadinejad said Iran also desired that, but added that his government wanted to see the whole world free of nuclear weapons.
"We believe that these weapons, possessed by the superpowers and the occupiers in our area, are a threat to stability," he said.
International worries about Iran's intentions have been intensified by Ahmadinejad's belligerent talk about Israel, including his comment that the Jewish state should be wiped "off the map."
Israeli Defense Minister Shaul Mofaz on Monday denounced Iran's negotiations with Russia as a bid to buy time to develop nuclear arms, but said Israel was willing to let diplomacy run its course for now.
He added, however, that Israeli leaders could not stand by indefinitely waiting for Iran's program to be reined in and said Israel will take all necessary steps to defend itself from a possible Iranian nuclear attack.
"As for the possibility of an Israeli attack (on Iran), I think it is not at all right to address this question publicly, but it can be said that Israel has the right and the obligation to do all that is necessary to defend itself," Mofaz told a group of high school students.
Israeli warplanes destroyed Iraq's Osirak nuclear reactor in a 1981 strike using conventional munitions.