US Secretary of State Condoleezza Rice dismissed a letter that Iran's president sent to US President Bush on Monday, saying the first direct communication from an Iranian leader in 27 years does not help resolve the standoff over Tehran's disputed nuclear program.

Secretary of State Condoleezza Rice is interviewed at the offices of the Associated Press in New York Monday, May 8, 2006. President Bush said Rice would go to the United Nations on Tuesday to press for a new U.N. resolution increasing peacekeepers in the Darfur region of Sudan. [AP]

Iran's top nuclear negotiator called the surprise letter a new "diplomatic opening" between the two countries, but Rice said it was not.

"This letter is not the place that one would find an opening to engage on the nuclear issue or anything of the sort," the top US diplomat said in an interview with The Associated Press. "It isn't addressing the issues that we're dealing with in a concrete way."

Rice said the letter from Iranian President Mahmoud Ahmadinejad was 17 or 18 pages long and covered history, philosophy and religion.

Rice's comments were the most detailed response from the United States to the letter, the first from an Iranian head of state to an American president since the 1979 hostage crisis at the US Embassy in Tehran.

She would not discuss the contents in detail but made clear that the United States would not change its tack on Iran.

"There's nothing in here that would suggest that we're on any different course than we were before we got the letter," Rice said.

The United States has had no diplomatic ties and almost no economic relationship with Iran since the storming of the embassy and the kidnapping of US diplomats.

Rice was using a two-day trip to the United Nations to confer on the international response to Iran, but she said she expected no quick action on sanctions or other measures.

The letter, which was not made public, appeared timed to blunt the US drive for a UN Security Council vote this week to restrain the Islamic regime's nuclear ambitions. It was a striking change after the fiery Ahmadinejad's campaign to vilify Washington and its allies as bullies.

US Secretary of State Condoleezza Rice speaks after a meeting of the Security Council at the United Nations in New York, May 9, 2006. Foreign ministers of major powers failed to come up with a joint strategy for dealing with Iran after Tehran sought to influence the negotiations with a stunning last-minute diplomatic maneuver, officials said. [Reuters]

Iran contends it has the right to process uranium as fuel in nuclear reactors to generate electricity. The United States, Britain and France are concerned that the program is a cover for making nuclear weapons.

White House press secretary Scott McClellan said Bush had been briefed on the letter, which the White House received Monday through the Swiss Embassy in Tehran. He would not comment on whether it was actually signed by the Iranian president.

"It does not appear to do anything to address the nuclear concerns" of the international community, McClellan told reporters traveling on Air Force One with Bush to Florida.

The Iranian government spokesman who disclosed the communication did not mention the nuclear standoff and said the missive spoke to the larger US-Iranian conflict.

The linchpin to any better understanding between Washington and Tehran, however, would be movement toward a solution of the nuclear issue.

According to government spokesman Gholam-Hossein Elham, the letter proposed "new solutions for getting out of international problems and the current fragile situation of the world."

Elham declined to reveal more, stressing "it is not an open letter." And when he was asked if the letter could lead to direct US-Iranian negotiations, he replied: "For the time being, it's just a letter."

In Turkey, Ali Larijani, Iran's top nuclear negotiator, said the Iranians were looking for a positive response but would be patient.

"Perhaps it could lead to a new diplomatic opening. It needs to be given some time," Larijani said in a television interview. He cautioned that the "tone of the letter is not something like softening."

The United States has publicly sought renewed contact with Iran through its ambassador in Iraq, Zalmay Khalilzad, who has been authorized to speak to Iranian officials about security in Iraq.

US officials say the talks await selection of a new Iraqi government and were to be limited to Iraqi security issues. Such meetings would provide an opportunity to broaden discussions about the US-Iranian relationship.

Before the Ahmadinejad letter was announced, Bush said he was paying close attention to threats made against Israel by Ahmadinejad, who has questioned Israel's right to exist and said the country should be wiped off the map.

"I think that it's very important for us to take his words very seriously," Bush told the German newspaper Bild on Friday, according to a transcript released Sunday. "When people speak, it is important that we listen carefully to what they say and take them seriously."

Foreign Minister Manouchehr Mottaki delivered the letter to the Swiss ambassador Monday, ministry spokesman Hamid Reza Asefi told the AP. The Swiss Embassy acts as a US interest section in the Iranian capital.

The letter appeared as the lead item on several Iranian television and radio news shows throughout the day. The official IRNA announced the letter and carried international reaction to it. Iran's only evening daily, the state-owned Ettalaat, carried a large story on its front page under the headline: "Important letter from Ahmadinejad to the American president."

On Tuesday, Ahmadinejad travels to Indonesia, where Foreign Minister Hassan Wirajuda said, "We support nuclear development for peaceful purposes, especially energy, but we consistently object to nuclear weapons proliferation."

The United States is backing efforts by Britain and France to win Security Council approval for a UN resolution that would threaten possible further measures if Iran does not suspend uranium enrichment. If taken to sufficient levels, the process can produce fuel for nuclear warheads.

Russia and China, the two other veto-holding members of the Security Council members, oppose sanctions.