Trump's 'empty threats' not worthy of response, says Rouhani

Iran's President Hassan Rouhani says there's no need to respond to President Donald Trump's "empty threats", two days after the US leader tweeted an all-caps warning of a future conflict with the Islamic republic.

Rouhani's remarks during a cabinet meeting on Wednesday were his first since Trump warned the Iranian leader in a much-mocked outburst of dire consequences for threatening the United States.

Rouhani said there are "baseless comments and empty threats" by "some US leaders."

He added: "There is no need for us to respond to any nonsensical comment and answer back to them."

Rouhani also said: "We should respond to them with action."

He added Iran's "strongest response to their cheap comments" would be "indifference to their plots and choosing to resist and foil their schemes".

Comment: Trump is manufacturing a crisis with Iran, just so he can 'solve' it later

Trump's Twitter outburst late on Sunday to Rouhani - all in capital letters, the digital equivalent of shouting - sparked questions about Washington's strategy towards the Islamic republic.

The US is regularly suspected of backing the idea of regime change, but analysts say its current stance may simply be an attempt to pivot after a week of dire headlines over Trump's much-maligned summit with Russia's Vladimir Putin and a relative lack of progress on North Korea.

"NEVER, EVER THREATEN THE UNITED STATES AGAIN OR YOU WILL SUFFER CONSEQUENCES THE LIKES OF WHICH FEW THROUGHOUT HISTORY HAVE EVER SUFFERED BEFORE," Trump warned Rouhani on Twitter.

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

On Tuesday, Trump tempered his tweet, saying "we're ready to make a real deal" with Iran.

Speaking to a national convention of the Veterans of Foreign Wars, Trump took credit for pulling the US out of the Iran nuclear accord, but said his administration stands ready for Iran to come back to the negotiating table. 

"We're ready to make a real deal, not the deal that was done by the previous administration, which was a disaster," he said.

Having withdrawn from the landmark 2015 nuclear accord between Tehran and world powers, Washington is piling on economic pressure with less than two weeks before re-imposing sanctions that had been lifted under the 2015 nuclear deal.