Tehran may prolong the war until US President Donald Trump’s term ends, according to a senior adviser to Iran’s Islamic Revolutionary Guard Corps.
Meanwhile, the US and Iran remain at odds over the Strait of Hormuz.
Trump claims the US has full control over the key waterway.
However, commercial shipping through the strait has fallen to its lowest level in a week. Iran says the strait will remain closed until its demands are met.
The US military says 59 commercial ships have changed course following the renewed naval blockade of Iran.
The IEA warns the crisis could cut global oil production by 4.3 million barrels a day this year.