Iran's supreme leader yesterday rejected an offer from the United States for direct talks on Tehran's nuclear programme.
Ayatollah Ali Khamenei said such talks could not take place while the US was tightening sanctions and threatening military action.
Washington is proposing talks while "pointing a gun at Iran", said the ayatollah, 73, insisting the US was in the weaker position.
"American policy in the Middle East has been destroyed and Americans now need to play a new card. That card is dragging Iran into negotiations," the ayatollah told air force commanders on his website.
"I am not a diplomat but a revolutionary and I speak frankly."
The Iranian president Mahmoud Ahmadinejad echoed the ayatollah's comments, saying talks would be meaningless if the US was "raising a club" against Iran.
"Talks are meaningful only if they are based on mutual respect, justice and equality," he said.
Meanwhile, Iranian state TV broadcast film it said was taken from a CIA spy drone Tehran claims to have captured in the country's airspace in December 2011.
On Saturday, US vice president Joe Biden proposed direct talks with Iran, separate from wider international discussions due this month.
A day later, Iran's US-educated foreign minister, Ali Akbar Salehi, welcomed the offer.
But on Wednesday, Washington tightened sanctions against Iran.
The move was aimed at cutting deeper into Iran's ability to obtain oil revenue, which has already fallen by 45 per cent in the past year.
The ayatollah, who has the final say on all key issues in the Islamic republic, said negotiations with the US "would solve nothing".
He has a visceral mistrust of Washington and is convinced the US is using the nuclear issue as a pretext to bring about regime change in Tehran.
Iran insists its atomic programme is peaceful in nature, while western powers and Israel say it is aimed at achieving a weapons capability.
Washington severed relations with Iran in 1980 after the storming of its embassy in Tehran by radical students who held 52 American diplomats hostage for 444 days.
Contacts between Iran and the US are limited to talks between Tehran and the so-called P5+1, comprising the five permanent members of the UN Security Council - the US, Russia, China, Britain and France - along with Germany.
After an eight-month hiatus, Iran is due to resume talks with the P5+1 on February 26 in Kazakhstan.