Tehran and Washington were scheduled to meet for a fourth round of talks in Rome on Saturday, after reporting progress in three rounds since April 12.

"The next round of indirect Iran-US talks, which were scheduled to be held in Rome on Saturday... has been postponed," Iranian foreign ministry spokesman Esmaeil Baqaei said in a statement.

He said the decision had been taken "based on the proposal of the Omani minister".

Omani Foreign Minister Badr Albusaidi cited "logistical reasons" for the delay.

"For logistical reasons, we are rescheduling the US-Iran meeting provisionally planned for Saturday May 3. New dates will be announced when mutually agreed," he said on X.

A source familiar with the talks said the United States "never confirmed its participation" in the fourth round planned for Saturday.

The source added that rearranged talks were expected to "take place in the near future."

Ahead of the Tehran-Washington talks, Iranian diplomats had been due to meet in Rome on Friday with representatives of Britain, France and Germany.

It was not immediately clear if those talks would go ahead as scheduled.

Since returning to office in January, Trump has revived his "maximum pressure" policy towards Tehran.

In March, he wrote to Iran's supreme leader Ayatollah Ali Khamenei proposing talks but warning of possible military action if diplomacy failed.

Western governments have long accused Iran of seeking to acquire a nuclear weapons capability -- an ambition Tehran has consistently denied, insisting its programme is for peaceful purposes only.

burs-mz/kir