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.
5 dead, more than 80 missing after Philippine ferry fire
US military says it struck vessel in Caribbean, killing 3
At least 14 killed in explosion at weapons depot in Syria
US hits five Iranian oil tankers after attack on Navy ships
UK gives air traffic provider a week to probe outage that halted flights
Serbia's President Vucic dissolves parliament, calls snap elections
With large crowds attending, Norway lays King Harald to rest
Jordan intercepts 18 Iranian ballistic missiles
