The State Department said the proposal to send a delegation led by US Senator Elizabeth Dole and possibly a member of President George W. Bush's family was entirely tied to last month's devastating earthquake in the city of Bam.

Although the mission would have been the first public official US visit to Iran in nearly 25 years, the department said the overture was not intended as a political signal.

"We're talking about two different issues," deputy spokesman Adam Ereli told reporters. "One is the humanitarian mission and one is better relations with Iran. The two aren't linked."

"I would specifically delink them," he said when asked about comments from Iranian officials suggesting that the United States had an ulterior motive in proposing the mission. "There is no common thread."

On Friday, Iran turned down the Dole mission, saying the time was not right and noting the severity of the situation in Bam where some 30,000 people died in the December 26 quake.

Iran had earlier accepted US offers of humanitarian assistance in the immediate aftermath of the disaster.

Although US officials, including Bush, have been insistant that improved political relations depend on Iran's behavior, Iranian officials began over the weekend to speculate on the motives behind Washington's offer.

On Sunday, the Iranian foreign ministry urged the Bush administration to clarify its policy and make further goodwill gestures if it was seeking a resumption of dialogue.

"In recent days we have heard different voices, so by consequence it is difficult to judge," spokesman Hamid Reza Asefi said. "It is not clear if this gesture is isolated or not."

On Saturday, Iranian Intelligence Minister Ali Yunessi said Tehran could not accept a US political mission and Foreign Minister Kamal Kharazi said "humanitarian issues should not be mixed up with political matters."

Ereli on Monday reiterated US demands for better ties with Iran.

"We're looking for Iran to take decisive action in a number of areas to address our concerns and that remains the case: cooperating in rendering al-Qaeda suspects there, getting rid of it WMD programs and stopping support for terrorist organizations," he said.

Iran and the United States cut diplomatic ties after the 1979 Islamic revolution saw the US-backed shah overthrown and 52 Americans held hostage at the American embassy here for 444 days.

In 2002, Bush lumped the Islamic republic into an "axis of evil" along with Saddam Hussein's Iraq and North Korea.

TERRA.WIRE