US President Donald Trump has announced a new round of talks with Iranian representatives after temporarily calling off further strikes on Iran.

The negotiations are due to take place on Monday, Trump told reporters on Sunday evening aboard Air Force One while travelling from New Jersey to Washington.

He did not say where they would be held, how long they might last or who would take part.

Trump also repeated that the US military had scrapped plans for a new wave of strikes on Iran at the last minute following appeals from Saudi Arabia, the United Arab Emirates, Qatar and Iran.

The planned attack "would have been the biggest attack since World War II and it would have been disastrous for them," Trump said.

Trump said he had called off the strikes after US allies told him that an agreement appeared to be close. Iran had also indicated that it wanted to reach a deal, he added.

Iran and the United States agreed in mid-June on a framework deal aimed at ending the war that began in late February.

Further details were to be worked out during a 60-day transition period, though doubts about the agreement's durability emerged from the outset and both sides have since carried out repeated major attacks.

Trump said on Saturday that he was suspending another wave of strikes because "the perimeters of a deal" had been agreed.

There has so far been no confirmation from Iran that a deal is close.