PARIS -- The top Iranian atomic energy official was quoted on Wednesday as saying that his country had begun to install more sophisticated enrichment devices at its Natanz nuclear site. The development coincided with the start of a new round of talks with negotiators from the United Nations nuclear watchdog.
Fereydoon Abbasi, the head of Iran's Atomic Energy Agency, said that scientists began putting in the new centrifuges last month, according to the semiofficial Iranian Students' News Agency. "We have produced the machines as planned, and we are carrying out the installation gradually, to complete the tests relevant to the new generation," he was quoted as saying.
Iran told the International Atomic Energy Agency, the United Nations nuclear regulatory body, late last month that it planned to install the new equipment at Natanz, southeast of Tehran, to speed up the production of enriched uranium, a move that seemed likely to worry the United States, Israel and the West.
But another Iranian news agency, Fars, quoted Mr. Abbasi as saying that the new centrifuges were designed to enrich uranium to a purity of less than 5 percent, not to the 20 percent level that prompts concerns about use in nuclear weapons.
On Tuesday, Iran said that it was converting some of its stockpile of 20-percent enriched uranium into reactor fuel. Diplomats in Vienna said that once that is done, it is difficult to reconvert it for weapons. Some analysts argue that, by slowing the growth of its stockpile, Tehran could be delaying the moment when it reaches a size large enough to prompt military action by Israel, which has signaled readiness to attack Iran's nuclear sites pre-emptively. Iran denies that it is seeking the wherewithal to build a nuclear weapon.
Iranian officials met in Tehran on Wednesday with Herman Nackaerts, the deputy director of the United Nations atomic agency, who has been pressing for months to gain access to a restricted military area at Parchin, 20 miles south of Tehran. International inspectors suspect that the site may have been used for testing bomb triggers.
"Differences remain, but we will work hard to try to resolve these differences," Mr. Nackaerts told reporters in Vienna before departing for Tehran, according to IRNA, the Iranian state news agency. He last met with the Iranian side, which is led by Ali-Asghar Soltaniyeh, the country's representative to the United Nations agency, on Jan 16.
After the meeting adjourned in the late afternoon, Mr. Soltaniyeh told Iranian reporters that the two sides exchanged new proposals and agreed on "some points," according to Reuters, which cited Press TV, the state-run English-language news channel. He said there would be further discussions but did not say when, Reuters reported. On a separate negotiating track, Iranian negotiators are scheduled to meet in Kazakhstan this month with representatives of six powers -- the United States, China, Russia, Britain, France and Germany -- for the next round in a long-running series of talks about curbing Iran's uranium enrichment program. So far those talks have been inconclusive.
Faced with economic sanctions, suspected cyberattacks and threats of military action against its nuclear facilities, Iran came under new pressure from President Obama in his State of the Union address to settle its differences with the West.
"The leaders of Iran must recognize that now is the time for a diplomatic solution, because a coalition stands united in demanding that they meet their obligations, and we will do what is necessary to prevent them from getting a nuclear weapon," Mr. Obama said.
Iran's nuclear program came under added scrutiny on Tuesday after North Korea conducted its third nuclear test, since many intelligence officials believe that the two countries share nuclear knowledge, though so far no hard evidence has surfaced to substantiate that belief.
This article originally appeared in The New York Times.