Tehran would consider any U.S. request to set up a diplomatic presence in Iran, the country's official news agency reported on Tuesday.
A Foreign Ministry official quoted by IRNA said "in principle, Iranian officials will consider requests they receive through formal channels."
On Monday, U.S. officials floated the idea of opening some sort of interests section in Iran.
Iran has operated an interests section in Washington for years. But the United States has not set up any diplomatic presence in Tehran since the 1979 Islamic Revolution and embassy hostage crisis.
The U.S. currently relies on the Swiss Embassy in Tehran to pass messages to the Iranian Foreign Ministry and handle the affairs of U.S. citizens in the country.
A U.S. interests section in Tehran would be similar to the one the State Department runs in Havana.
Like the one in communist Cuba, an interests section, or de facto embassy, in the Iranian capital would give the United States a presence on the ground through which it can communicate directly with students, dissidents and others without endorsing the government, one official said.
It would process visa applications and serve as a center for American cultural outreach to locals, the officials said, speaking on condition of anonymity to discuss internal deliberations.
The United States now has a small office in the Gulf state of Dubai that handles routine visa matters for Iranians but officials say it is not easily accessible and unable to do the work that an interests section could do.
The interests section concept is an old idea now being revisited by a very small group of diplomats and political officials at the State Department, with the blessing of Secretary of State Condoleezza Rice.
Rice declined to confirm or deny the idea, which was first reported in a Washington Post opinion column on Monday.
'Determined to reach out'
But, without being asked, she said the United States wanted more Iranians to come to the United States and hinted that the current arrangement in Dubai was not satisfactory.
"We know that it's difficult for Iranians sometimes to get to Dubai," she told reporters Monday aboard her plane en route to a conference in Germany. "We want more Iranians visiting the United States. ... We are determined to reach out to the Iranian people."
Rice is intrigued by the idea and has asked for an analysis of its feasibility and implications, the officials said.
The idea of an interests section has percolated at the State Department for several years, and was championed by the former third-ranking diplomat, Undersecretary of State Nicholas Burns, several officials said. The renewed effort is now being led by Burns' successor, William Burns, officials said.
William Burns, the officials said, is eager to demonstrate U.S. goodwill to the Iranian people even while tensions between the governments run high amid speculation that either the United States or Israel may use military force against Iran's nuclear facilities.
Burns and his backers see exchange programs and direct on-the-ground outreach to Iranians as the best way to overcome years of hostility, the officials said.