Iran has sent a response through Oman to President Donald Trump's letter in which he urged Tehran to reach a new nuclear deal, Iranian Foreign Minister Abbas Araqchi was cited as saying Thursday by the state run IRNA news agency.

"Our policy is still to not engage in direct negotiations while under maximum pressure and military threats, however, as it was the case in the past, indirect negotiations can continue," Araqchi said, according to the IRNA.

Earlier Thursday, Kamal Kharrazi, an adviser to Iran's supreme leader, said that Tehran has not closed all doors to resolve its disputes with the U.S. and is ready for indirect negotiations.

Tehran has so far rebuffed Trump's warning to make a deal or face military consequences. Supreme Leader Ayatollah Ali Khamenei called the message deceptive and Araqchi said talks are impossible unless the Trump administration changes its "maximum pressure" policy.

"Our response includes a letter in which we detailed our views on the current situation and Mr. Trump's letter," Araqchi said on Thursday.

In his first term, Trump withdrew the U.S. from a 2015 deal between Iran and world powers that placed strict limits on Tehran's nuclear activities in exchange for sanctions relief.

After Trump pulled out in 2018 and reimposed sweeping U.S. sanctions, the Islamic Republic breached and has since far surpassed those limits in its escalating program of uranium enrichment.

Western powers accused Iran of having a clandestine agenda to develop nuclear weapons capability by enriching uranium to a high level of fissile purity, above what they said is justifiable for a civilian atomic energy program.

Tehran said its nuclear program is wholly for civilian energy purposes.