The US should apologise for "crimes" it has committed against Iran if it wants a better relationship with Tehran, the Iranian president said today, after recent overtures to the Muslim world from the new administration in Washington.

Mahmoud Ahmadinejad's uncompromising tone followed a conciliatory message from Barack Obama, the US president, earlier this week when he told the Islamic world: "We are not your enemies." In his inauguration last week, Obama offered to extend a hand of peace if Iran "unclenched its fist".

At a rally in western Iran today, broadcast live on national television, Ahmadinejad said Iran would welcome a change in US policy provided it involved a withdrawal of American troops from abroad and an apology to Iran.

"Those who say they want to make change, this is the change they should make: they should apologise to the Iranian nation and try to make up for their dark background and the crimes they have committed against the Iranian nation," he said.

The Iranian leader listed a range of "crimes", such as trying to block what Tehran says is a peaceful nuclear power programme, hindering Iran's development since the 1979 revolution and other actions by US administrations dating back more than 60 years.

Ahmadinejad had harsh words for George Bush, who he said "has gone into the trash can of history with a very black and shameful file full of treachery and killings. He left and, God willing, he will go to hell."

In a break with his predecessor, Obama has dangled the prospect of direct talks with Tehran without preconditions. Susan Rice, the new US ambassador to the United Nations, has pledged "vigorous" and "direct" nuclear diplomacy with Iran but warned that pressure would increase if it refused to halt uranium enrichment.

Analysts believe Obama's election offers "a once-in-a-generation opportunity" for a new start in relations between Tehran and Washington, which were severed after students seized the US embassy in Tehran and took more than 90 hostages following the 1979 revolution.

"They will never get a new US president who is as balanced as Obama's public statements are, who talks about wanting to engage in a respectful way with Iran and who seems less encumbered by the baggage of the past," a western diplomat told the Associated Press. "It is in Iran's clear interest to engage." He warned of the risk that hardliners clinging to a "we're-winning-you're-losing rhetoric" may prevail.

An Iranian opposition politician, Ebrahim Yazdi, said he did not expect movement on the issue of US relations before June, when Ahmadinejad is expected to seek re-election. Yazdi said better ties were in Iran's strategic and economic interest, adding: "The political atmosphere in Iran is now ripe, is suitable for direct negotiation with the United States."

The five permanent members of the UN security council – Britain, China, France, Russia and the US – along with Germany have offered Tehran economic and energy incentives in exchange for halting its uranium enrichment programme, which the west sees as a cover to acquire a nuclear weapons capability. Tehran is pressing on with the programme, which it says is geared toward electricity generation.