WASHINGTON: Donald Trump has ‘warned’ the Iranian President Hassan Rouhani to carefully use his words against America and the American president.

“He [Rouhani] should better be careful,” Trump said, “the outcome of his words will harm his people.”

The war-of-words between Tehran and Washington escalated as President Hassan Rouhani and Trump traded threats and warnings after Iran’s nuclear test.

Rouhani told a crowd of hundreds of thousands marking the anniversary of the 1979 Islamic revolution that “the Iranian people must be spoken to with respect”.

“Iranians will make those using threatening language against this nation regret it,” he said.

Responding to US president’s statement, Rouhani said, “Anyone threatening Iran’s government and armed forces should know that our nation is vigilant.”

The US president has toughened the rhetoric against Iran considerably since coming to office. He also opposed the nuclear deal during the election campaign and termed it as “disastrous”.

Trump further asserted that it would be his “number one priority” to dismantle it.