Although there has been no official confirmation, European and American officials have said that the Bush administration was considering establishing an American diplomatic presence in Iran for the first time since relations were ended during the 444-day occupation of the American Embassy in Tehran, which started on Nov. 4, 1979.

The proposal would be to establish an interests section, rather than a fully staffed embassy, although the officials, who spoke on the condition of anonymity under diplomatic rules, have said that the idea has not been approved by the White House and that it could be delayed or blocked by opposition within the administration.

Speaking to reporters through a Turkish interpreter, Mr. Mottaki said that though he was open to talks on the issue, he was critical of the United States, saying that Iran had heard about the American plan only from the news media, instead of official channels.

On Saturday, William J. Burns, the State Department’s third-ranking official, was expected in Geneva to participate, along with European Union nations, in talks with Iran aimed at persuading it to suspend uranium enrichment in exchange for economic and political incentives. The European Union’s foreign policy chief, Javier Solana, and Tehran’s nuclear negotiator, Saeed Jalili, were to take part in the meeting.

The Iranian delegation has prepared its own proposals on political, economic and security issues, and was ready to discuss them in detail, Mr. Mottaki said. He described a more positive atmosphere that he said had been created after Mr. Solana’s recent visit to Tehran in June to present a document of understanding among the six countries participating in the nuclear talks  the United States, Germany, Russia, France, Britain and China.