Trump hits back at Iran 'war' talk

President Donald Trump on Sunday hit back at bellicose comments by Iran's president, warning him of dire consequences as the US intensifies its campaign against the Islamic republic.

"NEVER, EVER THREATEN THE UNITED STATES AGAIN OR YOU WILL SUFFER CONSEQUENCES THE LIKES OF WHICH FEW THROUGHOUT HISTORY HAVE EVER SUFFERED BEFORE," Trump said on Twitter in a direct message to President Hassan Rouhani.

Earlier Sunday the Iranian leader had warned Trump not to "play with the lion's tail," saying that conflict with Iran would be the "mother of all wars".

The US president, writing his entire message in capital letters, continued his riposte:

"WE ARE NO LONGER A COUNTRY THAT WILL STAND FOR YOUR DEMENTED WORDS OF VIOLENCE & DEATH. BE CAUTIOUS!"

His comments Sunday night came after Secretary of State Mike Pompeo, in a major address to the Iranian diaspora in California, said Washington is not afraid to sanction top-ranking leaders of the "nightmare" Iranian regime.

Trump in May pulled the US out of a hard-won agreement with Tehran, also signed by Britain, China, France, Germany and Russia, which lifted sanctions in exchange for curbs on Iran's nuclear program.

The 2015 agreement was in response to fears that Iran was developing a nuclear bomb.

European allies maintain their support for the deal and have vowed to stay in it, though their businesses fear US penalties.

Following Washington's pullout Pompeo unveiled Washington's tougher line under which, he said, the US would lift the new sanctions if Iran ended its ballistic missile program and interventions in regional conflicts from Yemen to Syria.

Rouhani immediately dismissed those US threats and on Sunday said: "You cannot provoke the Iranian people against their own security and interests."