US President Donald Trump said he could lift sanctions on Iran if the country demonstrates peaceful behaviour and cooperation with Washington.

"If they can be peaceful, and if they can join us, they are not going to do any more harm, I would take the sanctions off," Trump said in a Fox News interview aired Sunday.

"You get more sometimes with honey than you do with vinegar," Trump said, adding sanctions relief "would make a big difference" for Tehran.

He earlier halted sanctions relief work after Supreme Leader Ali Khamenei vowed to attack US bases if Washington renewed strikes against Iranian targets.

Uranium evacuation claims rejected

Trump reiterated his rejection of claims Iran evacuated enriched uranium before US strikes, citing the material's weight and logistical challenges.

The president said America "did not give much notice" before attacks, making material removal "hard" and "dangerous."

"They did not move anything. They did not think it was going to be actually doable what we did," Trump said.

He described Iran as "exhausted" from recent Israeli and American strikes, predicting nuclear activities would cease temporarily.

"Last thing they are going to be doing right now, for a period of time, at least, is nuclear. They have had it," Trump said.

Abraham Accords expansion anticipated

Trump said that some countries expressed interest in joining the Abraham Accord normalisation agreements between Israel and Arab states, though he did not specify which nations.

"We have some really great countries in there right now, and I think we are going to start loading them up, because Iran was the primary problem," he said.