US President Donald Trump said in an interview broadcast Sunday that he will not unfreeze Iranian assets before reaching an agreement with Tehran.

Asked whether he would be willing, as part of a potential agreement, to unfreeze Iranian assets or lift certain sanctions against Iran, Trump replied: "No."

"(That) comes after. If they behave, if they do a good job, we start talking," he said in the interview with NBC, recorded Friday.

Iran has demanded that billions in frozen assets be unblocked.

According to a source close to the matter, the US Treasury is considering the possibility that Iran's assets could be tapped to compensate Gulf states for damages caused by Iranian strikes.

Trump reiterated that he knows exactly where the enriched uranium is located in Iran and wants to recover it one way or another, while remaining vague about whether he would send in US troops to do so.

"If we make a deal, if we make a deal now we're friendly, we'll all go together" to recover this uranium, he said. "We'll take it out and destroy it."

The fate of the enriched uranium is one of the most difficult points in reaching an agreement to end the war waged by the United States and Israel against Iran.