"It has been fully agreed by and between Israel and Iran that there will be a Complete and Total CEASEFIRE," Trump wrote Monday evening on his Truth Social platform.

There was no immediate comment from Israel or Iran confirming the agreement.

As outlined by Trump, the ceasefire would be a phased 24-hour process beginning at around 0400 GMT Tuesday, with Iran unilaterally halting all operations. Israel would follow suit 12 hours later.

"Upon the 24th hour, an official end to the 12-day war will be saluted by the world," he said, adding that both sides had agreed to remain "peaceful and respectful" during each phase of the process.

Trump's announcement came just hours after Iran launched strikes against an American military base in Qatar, which he described as "weak" retaliation for US strikes over the weekend against Iranian nuclear sites.

Iran and Israel have exchanged wave after wave of air strikes since Israel unleashed a major military offensive on June 13.