Yukiya Amano, chief of the IAEA, says the nuclear watchdog agency is close to reaching a deal with Iran to give inspectors access to some nuclear sites.

AMMAN, Jordan — The United Nations´ atomic watchdog agency said it was close to a deal giving inspectors access to some of Iran´s disputed nuclear sites, providing a dose of optimism as diplomats prepared for new talks to overcome their standoff with the Islamic Republic.

Yukiya Amano, director-general of the International Atomic Energy Agency, said he expected to sign a deal with Iran "quite soon." He spoke to reporters in Vienna after returning from Tehran -- the first time Iranian officials had been willing to meet with him in their capital since he became head of the agency in 2009.

Amano, who has pressed hard for Iran to provide better access to its nuclear sites and personnel, told reporters he considered the deal to be "an important development," according to a transcript released by the agency.

The news came as diplomats from the U.N., the United States and five other major powers prepared to meet this week in Baghdad with Iranian officials for negotiations over Iran´s nuclear ambitions. Taken together, the developments appeared to ease tensions.

For months, talk of war has dominated discussions about Iran. The Tehran government insists its nuclear program is strictly for peaceful purposes, but officials in the U.S., Israel and some European countries suspect Iran is trying to build a nuclear weapon. Israeli officials have strongly suggested they might bomb Iranian nuclear sites if they believe the Iranian efforts have gone too far.

Obama administration officials have suggested recently that there may be grounds for optimism about diplomatic progress. U.S. officials were encouraged by the atmosphere at a mid-April meeting with Iranian officials in Istanbul, Turkey.

Some diplomats say they have seen signs that Iran, under crushing pressure from international economic sanctions, may be open to negotiating at least a preliminary deal.

Others, however, cautioned that the Iranians often have dangled concessions as a way to buy time. Israeli officials reacted skeptically to Amano´s announcement.

A senior U.S. official said Tuesday that an agreement between the IAEA and Iran would be a "good thing," but stressed that the IAEA´s investigations into Iran´s nuclear program "are about accounting for the past, not about the future."

The negotiations in Baghdad, in which Iranian officials will meet with diplomats from the U.S., Britain, France, China, Russia and Germany, are over future limits to Iran´s nuclear efforts and are therefore more consequential, the official said.

At those negotiations, the six world powers will press Iran to stop enriching uranium to 20% purity, a level at which the material can quickly be enriched to bomb grade, and to surrender the stockpile of highly enriched uranium it already has. In return, they are promising to provide Iran fuel for a small nuclear reactor used for medical purposes and to hold off on imposing additional U.N. sanctions.

But they are not promising what Iran wants most: relief from tough sanctions on its oil exports and its central bank that have been put in place since the end of last year. Those sanctions have severely disrupted Iran´s economy.

Ali Larijani, the speaker of the Iranian parliament, said Tuesday that it was improper for Western nations to continue adding sanctions, government-controlled Press TV reported.

Western diplomats have expressed concern for some time that Iran might try to satisfy IAEA calls for access to its facilities and scientists, then argue that it had done everything necessary to bring its program into compliance with international rules.

Amano, a veteran Japanese diplomat, has been demanding in particular that the Iranians open access to a military facility at Parchin. IAEA officials are concerned that the Iranians might have tested detonating devices there that would be suitable for use in nuclear weapons.

Amano didn´t say that Iran would grant access to the Parchin site. He said only that the question of access "will be addressed" in the deal. He also acknowledged that differences remain between the IAEA and the Iranians, though he emphasized that those disagreements would not stand in the way of a deal.

Israeli officials were unconvinced by Amano´s report of progress.

Defense Minister Ehud Barak said Iran appeared to be trying to create an "appearance of progress" to "reduce the pressure ahead of talks in Baghdad and to postpone an escalation in sanctions." He urged international negotiators to hold firm.

"Israel believes that Iran should be set a clear bar so that there is no window or crack the Iranians can proceed through toward a military nuclear program," he said. "The requirements of the world powers must be clear and unequivocal."

David Albright, president of the Institute for Science and International Security and a former weapons inspector, also expressed caution, saying he had concerns that the U.N. agency might have yielded important ground to obtain a deal.

"I have more worries than hopes," Albright said. "I just want to see what´s in the deal." Times staff writer Edmund Sanders in Jerusalem contributed to this report. (Copyright © 2012 Los Angeles Times 05/23/12)