"You should not negotiate with such a government, it is unwise, it is not intelligent, it is not honourable to negotiate," Khamenei said, adding the United States had previously "ruined, violated, and tore up" a 2015 nuclear deal.

The warning came days after US President Donald Trump called for a "verified nuclear peace agreement" with Iran, adding that it "cannot have a nuclear weapon".

Iran insists its nuclear programme is solely for peaceful purposes and denies any intention to develop atomic weapons.

"We must understand this correctly: they should not pretend that if we sit down at the negotiating table with that government (the US administration), problems will be solved," Khamenei said during a meeting with army commanders.

"No problem will be solved by negotiating with America," he said, citing previous "experience".

Trump, who returned to the White House on January 20, had on Tuesday reinstated his "maximum pressure" policy against Iran over allegations the country is seeking to develop nuclear weapons.

Under the tough policy of sanctions during Trump's first term, which ended in 2021, Washington withdrew from a landmark nuclear deal that had imposed curbs on Iran's nuclear programme in return for sanctions relief.

Tehran adhered to the deal -- known as the Joint Comprehensive Plan of Action -- until a year after Washington pulled out, but then began rolling back its commitments.

Efforts to revive the 2015 deal have since faltered.

During the meeting, Khamenei said Iran was "very generous" and made "concessions" during the negotiations which culminated in the 2015 deal but it "did not achieve the intended results."

"The same person who is in power now tore up the treaty," the supreme leader said.

He further warned Iran would take reciprocal measures if the US threatened or acted against Iran.

"If they threaten us, we will threaten them. If they carry out this threat, we will carry out our threat. If they attack the security of our nation, we will attack their security without hesitation," said Khamenei.