Iran's foreign minister makes a suprise visit to U.S.

One day before Iran meets in Geneva with the United States and other powers worried about its nuclear program, the State Department granted Mottaki's request to visit the Iranian interests section at Pakistan's embassy, which represents Tehran in Washington in the absence of diplomatic ties.

U.S.-based analysts and diplomats said it was the first such visit in years, possibly since Iran's Islamic Revolution in 1979.

"I wouldn't read too much into this ... It was a straightforward request and we granted it," State Department spokesman P.J. Crowley told a news briefing, saying there were no plans for Mottaki to meet U.S. officials or anyone acting on behalf of the U.S. government.

"As to what interactions he has here, I don't know. I refer you to the Iranians."

The United Nations announced Mottaki will give a news conference at U.N. headquarters in New York at 11 a.m./1500 GMT on Thursday -- coinciding with the Geneva talks.

Crowley declined to describe the U.S. move to allow Mottaki's visit as a gesture before the talks, which U.S. President Barack Obama has described as a chance for Tehran to allay rising Western fears that its nuclear program has military aims.

"We are far more interested in having Iran come tomorrow to Geneva and we hope that they will be the ones who are offering gestures that they are ready to address concerns that the international community has," he said.

But a U.S. official acknowledged the possibility that the visit could set a better tone for Thursday's meeting.

"From our standpoint the really important meeting is tomorrow," said a U.S. official who spoke to reporters on condition he not be identified. "If this gesture today leads us in a constructive direction tomorrow, terrific."

One Iran analyst said the visit could help to show Tehran that Washington is serious when it offers improved ties in return for greater transparency on the nuclear issue.

"I doubt that a (Washington) DC trip alone will make the difference, but it may help demonstrate that the administration is not simply going through the motions of engagement," Suzanne Maloney, a senior fellow at the Brookings Institution's Saban Center for Middle East Policy, said in an email message.

The one-day talks in Switzerland will bring the five permanent members of the U.N. Security Council -- the United States, Britain, France, Russia and China -- together with Germany to meet Iranian officials.

Tehran has repeatedly said it will refuse to negotiate over its nuclear program, which it describes as peaceful.

The United States and other powers have suggested Iran could be subjected to more economic and political sanctions if it fails to increase transparency over its uranium enrichment program.