Iran has turned down the US offer of a high-level humanitarian delegation to deliver earthquake relief.
Iran said the time was not right for the planned delegation to visit
US officials planned to send Senator Elizabeth Dole, a former head of the American Red Cross, on the mission.
But the state department said the Iranians were holding the visit "in abeyance" and the US had decided not to pursue it for the moment.
Earlier an Iranian cleric accused the US of trying to exploit the disaster, which killed more than 30,000 people.
The US authorities have already eased sanctions on Iran to allow Americans to make financial donations for disaster relief. An American medical and disaster relief team is also working in the country.
US state department deputy spokesman, Adam Ereli, said the US delegation offer was made for humanitarian, and not political, reasons.
"We don't see the response as political either," he said.
The BBC's John Leyne, in Washington, says the Iranian response shows that Tehran seems unwilling to move from humanitarian aid to more of a political reconciliation.
US aid workers are already helping in Bam's relief effort
President George W Bush has said America's easing of some sanctions and its readiness to help Iran, after last week's earthquake, does not signal a change in Washington's policy.
Meanwhile, hard-line right-winger, Ayatollah Ahmad Jannati, said at Friday prayers in Tehran: "Naturally America wanted to take advantage of this situation by offering some help and bringing up the issue of relations."
But the BBC's Jim Muir, in Tehran, says that unusually his remarks were not carried in the lunchtime bulletins of the main state television channel and they were toned down in the official Iranian news agency account.
The US severed ties with Iran after the 1979 Iranian revolution. Iranian students had seized 63 hostages at US embassy in Tehran.
President Bush has since described Iran as part of an "axis of evil" along with North Korea and Iraq.
Mr Ereli said Washington had approached Iran on the subject of a visit after Tehran accepted a US aid shipment for the people of Bam.
An unnamed member of the Bush family was to have accompanied Senator Dole.
The mission would have been the first official US visit to Iran since 1979.
In a recent interview, Secretary of State Colin Powell also held out the possibility of a new dialogue with Tehran.
Iranian President Mohammad Khatami has pledged to rebuild the ancient city of Bam.
The head of the reconstruction team, Hamid Eskander, has said the task is huge but not impossible.
Workers have cleared away most of the victims' bodies from the earthquake site.
The United Nations plans to complete an assessment of the needs of Bam by the middle of next week which will be presented to international donors.
Most residents have either left the city or are sheltering in tents.