A handout picture provided by the office of Iranian President Hassan Rouhani on August 2, 2016 shows him giving a televised speech in Tehran.

Iranian President Hassan Rowhani warned Friday that those using “threatening language” against Tehran would regret it as the regime faces increasingly hawkish rhetoric from the new US administration.

Rowhani was speaking at a march attended by hundreds of thousands of people in the capital marking the anniversary of the 1979 Islamic revolution.

“This turnout is a response to false remarks by the new rulers in the White House and the people are telling the world through their presence that the Iranian people must be spoken to with respect,” Rowhani said.

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

“Anyone threating Iran’s government and armed forces should know that our nation is vigilant.”

US President Donald Trump has taken an increasingly strident line towards Iran since taking office last month, warning that it was “playing with fire” and “on notice”.

Last week, he imposed sanctions on Iran over a January 29 ballistic missile test and officials warned more might follow.

Last weekend, new Pentagon chief James Mattis described Iran as “the single biggest state sponsor of terrorism in the world.”

Iran’s supreme leader Ayatollah Ali Khamenei said on Tuesday that Trump’s policies showed “the real face of America”, a country long derided by the regime as the “great Satan”.