US vice president JD Vance has sent a letter to Mohsen Rezaei proposing to restart talks, US officials said on Wednesday.

Rezaei is secretary of Iran's Supreme National Security Council. He is one of the most influential hardliners and is close to supreme leader Mojtaba Khamenei.

A US official said Donald Trump ordered the letter and knows about the move. Vance wants to see if there is enough common ground to persuade Trump not to restart the military campaign. The US and Israel launched it in late February, eight months ago.

A source familiar with the talks said neither the letter nor the exchange that followed between US and Iranian officials sets out specific terms for a new ceasefire. They only outline a framework for resuming talks.

Vance publicly backs the war but privately has doubts about prolonging it. Before the campaign began, he pushed for more diplomacy. Trump put him in charge of the US negotiating team, and Vance has twice travelled to meet Iranian officials to try to reach a final deal.

Administration officials believe direct contact with Iran's hardliners may produce better results. If Rezaei becomes the main contact, foreign minister Abbas Araghchi and parliament speaker Mohammad Bagher Ghalibaf could be left out. Last week Rezaei said Iran would not negotiate with Washington until certain basic demands were met.

Days earlier, Trump said the administration was not negotiating with Tehran and hinted at new strikes soon. "We're not negotiating with them. One way or another something will happen, and it will happen soon," he said. Strikes are expected, probably after the US midterm elections on 3 November.

Washington has called on several Gulf Arab states to prepare for a possible short but intense campaign against Iran after the elections. The warnings reached governments through diplomatic and military channels.

Earlier this week in Tehran, senior officials from Saudi Arabia, Turkey and Pakistan met Iranian officials, including Rezaei, to ease tension in the region. It was the first high-level talks between Iran and the three countries.

The three countries belong to the Mecca Pact, a mutual defence agreement under which an attack on one is an attack on all. Iran has been mentioned as a possible future member. The pact's effectiveness is in doubt after new attacks on Saudi Arabia by the Houthis in Yemen, while Egypt approved defence aid for Riyadh.

After the elections in Israel, prime minister Benjamin Netanyahu began his speech to Likud supporters with Iran.