Ammon News - US envoy Steve Witkoff said on Saturday that President Donald Trump is questioning why Iran has not "capitulated" in the face of Washington's military build-up aimed at pressuring them into a nuclear deal.

The United States and Iran this week resumed Oman-mediated talks in Geneva aimed at averting the possibility of military action, after Washington dispatched two aircraft carriers, jets and weaponry to the region to back its warnings.

In a Fox News interview with Trump's daughter-in-law Lara, Witkoff said the president was "curious" about Iran's position after he had warned them of severe consequences in the event they failed to strike a deal.

"I don't want to use the word 'frustrated,' because he understands he has plenty of alternatives, but he's curious as to why they haven't... I don't want to use the word 'capitulated,' but why they haven't capitulated," AFP quoted him as saying.

"Why, under this pressure, with the amount of seapower and naval power over there, why haven't they come to us and said, 'We profess we don't want a weapon, so here's what we're prepared to do'? And yet it's sort of hard to get them to that place."

The US envoy also confirmed in the interview that he had met with Reza Pahlavi, who has not returned to Iran since before the 1979 Iranian Revolution that ousted the monarchy.

"I met him at the direction of the president," he said, without providing further details.

US-based Pahlavi last week told a crowd in Munich that he was ready to lead the country to a "secular democratic future" after Trump said regime change would be best for the country.

Witkoff's comments come after Iranian Foreign Minister Abbas Araghchi said a draft proposal for an agreement with Washington would be ready in a matter of days.

Trump said on Thursday that Iran had at most 15 days to make a deal on concerns starting with its nuclear program.

As talks between the two nations continued in Geneva, Iran's supreme leader Ali Khamenei on Tuesday said that Trump would not succeed in destroying the country.