ISTANBUL, Turkey — International pressure on Iran to prove it is not developing nuclear weapons increased Monday as the chief of the U.N. atomic watchdog agency said he would visit Tehran this week and Russia postponed plans to start up a nuclear reactor in Iran.
Mohamed ElBaradei, director-general of the International Atomic Energy Agency, and senior officials of his organization would visit Tehran in an attempt to persuade Iran's leaders to meet an Oct. 31 deadline to suspend its nuclear enrichment program and permit intensive inspections of its nuclear sites.
"Time is indeed running out," ElBaradei said in a statement released Monday, adding that Iran had not provided a full accounting of its nuclear activities.
The IAEA imposed the deadline last month in response to suspicions that Iran's civilian nuclear program conceals efforts to build a weapon. Concerns have grown in recent weeks after inspectors found traces of weapons-grade uranium at two sites in Iran.
Officials in Tehran said the uranium came on contaminated equipment purchased abroad. They insisted that Iran's nuclear program was devoted solely to generating electricity and have resisted what they regard as U.S.-inspired pressure from the IAEA.
"We will not allow anyone to deprive us of our legitimate right to use the nuclear technology, particularly enrichment, for providing fuel for our plants," Kamal Kharrazi, Iran's foreign minister, was quoted as saying last week by the Islamic Republic News Agency.
Russia is building Iran's first nuclear reactor near the Persian Gulf port of Bushehr. U.S. officials fear the reactor could produce fissile material for an atomic weapon, and they have been pressuring the Russians to withdraw from the project.
On Monday, Russia's Atomic Energy Ministry said it was postponing plans to start the reactor for a year, which means it would go online in 2005. It said the delay was caused by technical problems, not by political reasons.
"We are putting off the start-up of the first reactor of the Bushehr plant because much of the technical equipment has not been supplied in time," a ministry official told Reuters.
While several installations are suspected of playing a role in Iran's alleged nuclear weapons program, U.S. officials said they were most concerned that Iran could divert low-enriched uranium from Bushehr to a weapons facility, where it could be further enriched to manufacture an atomic bomb.
"You could not stop the program entirely, but if Bushehr never came online, you would not get the low-enriched uranium to divert to weapons," said a senior Bush administration official.
The German magazine Der Spiegel reported this week that Israel had identified several hidden nuclear weapons installations in Iran and was making plans to destroy them if necessary.
An Iranian opposition group said Monday that it planned to release information today about secret nuclear facilities in Iran. The group, the National Council of Resistance of Iran, has provided accurate information in the past.
Iranian officials are debating whether to comply with the Oct. 31 deadline and whether to sign an agreement that would give IAEA inspectors the right to conduct more intrusive inspections of its nuclear installations.
If Iran fails to satisfy the agency, the issue could be referred to the U.N. Security Council, which could impose sanctions. The IAEA's board of governors from 35 countries is set to meet Nov. 20 to determine whether Iran has complied.