TEHRAN, Iran (AP) – The chance for breakthrough contacts between Iran and United States is rapidly dimming.

Washington has ruled out any direct negotiations on Tehran’s nuclear program and Tehran is publicly saying it doesn’t want the previously agreed talks on Iraq, even as it continues to put out back-channel feelers.

Only months ago, the two bitter enemies were saying they would hold high-level meetings on how to stabilize war-torn Iraq, where Iran holds enormous influence. That raised hopes that talks could also begin on the more burning dispute over Iran’s nuclear ambitions.

But in Washington, White House press secretary Tony Snow said Wednesday that the United States would not consider direct talks with Iran on the nuclear issue until it ends all uranium enrichment, something Iran has refused, and allows international inspections to verify.

“When that happens, all right, then there may be some opportunities,” Snow said. But he would not elaborate. “I’m going no further,” he said.

At the same time, U.S. officials have made overtures to say they are ready for talks on Iraq.

The U.S. ambassador to Baghdad, Zalmay Khalilzad, said Sunday the time was ripe now that Iraq’s new government was formed, and Secretary of State Condoleezza Rice went on Arab television Tuesday to say Washington recognizes Iran’s role in Iraq, as long as it is constructive.

But with the nuclear dispute intensifying, Iran has taken a tougher public line.

Iranian officials made no comments on Rice’s statements. But earlier this week, the Foreign Ministry spokesman, Hamid Reza Asefi, appeared to close the door: “We don’t see any need to talk to America about Iraq” since a government has already been formed.

Iran’s hard-line president, Mahmoud Ahmadinejad, blasted the United States on Wednesday, accusing it of seeking to stir up trouble among Iran’s ethnic minorities. But even as it takes that hard public line, Iran has been showing interest in holding talks with the United States through intermediaries, State Department spokesman Sean McCormack confirmed on Wednesday. He did not identify the intermediaries, and said the U.S. had not replied to the overtures.

The U.N.’s main nuclear negotiator, however, appeared to confirm he was one of the intermediaries, saying he had met with Iranian nuclear negotiator Ali Larijani several days ago. The U.N. head, Mohammed ElBaradei, said he then described to Rice “the Iranian point of view, which is rather different from the U.S. point of view.”

The Washington Post also reported this week that Iran was using back channels to seek direct talks with the United States over its nuclear program, quoting unidentified U.S. officials and diplomats.

The faltering diplomacy underlines the delicacy of attempts to overcome 27 years of estrangement since the seizure of the U.S. Embassy after Iran’s 1979 Islamic Revolution.

The only publicly acknowledged discussions between the two countries came in early 2003, among lower-level officials in preparation for the U.S.-led invasion of Iraq. Both nations also have sat together in some regional diplomatic groups, including talks after the fall of the Taliban in Afghanistan in 2001.

Tehran has long publicly rejected one-on-one talks with the nation it calls the “Great Satan,” but its initial acceptance of an Iraq meeting, and its back-door efforts toward talks, show it sees a benefit in sitting down with the United States.

Iran seeks to maintain its influence with majority Shiite Muslims in Iraq and is desperate to avoid possible U.N. Security Council sanctions over its nuclear program, which Tehran claims is only for peaceful energy purposes, but the United States and allies fear is a cover for eventual weapons development.

The five permanent Security Council members and Germany met in London on Wednesday to examine possible incentives for Iran to drop its uranium enrichment program. “Nobody in the government opposes the talks, but the problem is that they cannot convince ordinary people overnight, since during the past 27 years Iran’s government openly opposed any contact with the United States,” said Mostafa Mirzaian, an independent political researcher based in Tehran.

In March, Supreme leader Khamenei had to come out and publicly state his approval for the Iraq meetings proposal after some hard-liners sharply criticized the idea.

Larijani, the chairman of Iran’s Supreme National Security Council, has traveled to several key U.S. allies this month.

In Greece, which currently holds one of the non-permanent Security Council seats, he met with the foreign minister, whose family has a long friendship with the Bushes. But it’s unclear whether these visits also included bids to reach out to Washington. The Greek Foreign Ministry declined to give specific details of the May 9 meeting.