US President Donald Trump warned late on Sunday that “there won’t be anything left of Iran” if it doesn’t quickly agree to the United States’ demands and enter into a deal to secure a permanent ceasefire, threatening a resumption of hostilities with increased intensity.

“For Iran, the Clock is Ticking, and they better get moving, FAST, or there won’t be anything left of them. TIME IS OF THE ESSENCE!” wrote Trump on his own social media platform, Truth Social.

Washington, locked in conflict with Tehran since US and Israeli forces launched major strikes on the Islamic republic beginning 28 February, has struggled to break an impasse and make any progress towards ending a war that has upended the Middle East and sent global energy prices soaring.

The war has led to an effective blockade of the critical Strait of Hormuz, through which one-fifth of the world’s oil exports pass in peacetime, and has drawn neighbours Israel and Lebanon into a deadly side-conflict.

Iran's clerical state, Hezbollah's patron, has demanded a lasting ceasefire in Lebanon before any broader peace agreement with Trump, who has been frustrated by Tehran's refusal to an agreement on his terms. Both sides have repeatedly expressed their readiness to resume the fighting.