In his first remarks read on state television since taking over, Iran's new supreme leader Mojtaba Khamenei has vowed to keep the Strait of Hormuz closed.
He said the strait, which runs past Iran's coast and supplies a fifth of the world's oil, should remain shut to "put pressure on the enemy".
He also said the US must close all its bases in the region.
The war that began with a US-Israeli bombing campaign at the end of February has so far killed around 2,000 people and caused what the International Energy Agency describes as the biggest disruption to global energy supplies in history.
Trump cancels US strikes on Iran, citing progress in talks
US confirms third strike on Indian-crewed tankers this week
UK defence minister Healey quits, says PM Starmer's plans fail to keep country safe
False alarm at the Pentagon triggers brief shelter-in-place order
Trump says US will hit Iran 'very hard', take control of energy infrastructure
US and Iran trade attacks for a second day, undermining shaky ceasefire
Bahrain says debris from intercepted Iranian drones injures child, damages homes
Philippines launches probe into deaths of two athletes from top basketball team
