Iran's president says the US should "put warmongers aside" as tensions roil the Persian Gul amid an escalating crisis between Washington and Tehran in the wake of the collapsing nuclear deal with world powers.

Hassan Rouhani's remarks signalled approval of President Donald Trump's abrupt dismissal of John Bolton as national security adviser. Bolton had been hawkish on Iran and other global challenges.

Rouhani's website quoted him on Wednesday as further urging the US to "abandon warmongering and its maximum pressure policy" on Iran. He spoke at a cabinet meeting in Tehran.

Ali Rabiei, a government spokesman, said after the meeting that Bolton's dismissal may help the US have a "less biased" attitude toward Iran.

Trump last year pulled the US out of the nuclear deal and intensified sanctions on Iran.