(Reuters)- Iran's supreme leader suggested on Thursday that ties might one day be possible with the United States, the Islamic state's arch foe for almost three decades, although he said it would harm Iran to restore relations now.
"Not having relations with America is one of our main policies but we have never said this relationship should be cut forever," Ayatollah Ali Khamenei said in the central province of Yazd , state television reported.
"Certainly, the day when having relations with America is useful for the nation I will be the first one to approve this relationship."
The United States severed ties shortly after Iran's 1979 Islamic Revolution and the seizure of the U.S. embassy in Tehran. They are at odds over Iran's atomic ambitions and also disagree over who is to blame for the violence in Iraq.
Iranian leaders have often said they would not establish ties with the United States unless Washington, which is leading efforts to isolate Tehran over its nuclear work, changes its behavior towards the Islamic Republic.
U.S. Secretary of State Condoleezza Rice said last month Washington was open to better relations with Iran if it halted its nuclear work, something Tehran has repeatedly refused to do.
The West suspects Iran wants to master nuclear technology so it can build atomic bombs. Iran, the world's fourth-largest crude producer, says its program is aimed at generating electricity to enable it to sell more oil and gas.
Washington is pushing for a third round of U.N. sanctions against Iran over its atomic activities, even though a U.S. national intelligence estimate last month said Iran had stopped its nuclear weapons program in 2003.
Khamenei , who like other Iranian leaders often rails against the West, suggested the example of Iraq showed the United States would remain a "danger" even if the two countries had relations.
"Because of America's conditions ... establishing this relationship now would be harmful for us and naturally we shouldn't follow it," he said.
"Some accuse us of provoking the enmity of America but their enmity towards Iran ... is towards the principles of the Iranian nation."
Iranian and U.S. officials eased a diplomatic freeze last year by holding three rounds of talks in Baghdad since May, but those discussions were limited to Iraq.
Khamenei rejected the suggestion by Washington and Moscow that Iran should stop its own nuclear uranium enrichment after Russia began delivering fuel in December to Iran's first atomic power plant in Bushehr .
"This is like telling a country with huge oil reserves that it should provide for its oil needs from abroad," he said.
Enriched uranium can be used as fuel for power plants but also, if refined much further, provide material for bombs.
Iranian officials say the country needs domestic nuclear fuel production for other power plants it wants to build.
"The Americans had no choice but to accept their failure in stopping Iran's nuclear achievements," Khamenei said.