United States President Donald Trump has said that Washington is considering “strong options” in response to Iran’s crackdown on anti-government protests, including possible military intervention.

We’re looking at it very seriously. The military is looking at it, and we’re looking at some very strong options. We’ll make a determination,” he told reporters on board Air Force One late on Sunday.

He said Iran’s leadership had called, seeking “to negotiate” after his threats of military action, and that a “meeting is being set up”.

But he added that “we may have to act before a meeting”.

There was no immediate comment from Tehran.

Iranian leaders earlier on Sunday issued a stark warning against military intervention, with Parliament Speaker Mohammad Baqer Qalibaf saying: “In the case of an attack on Iran, the occupied territories [Israel] as well as all US bases and ships will be our legitimate target.”

The protests in Iran began on December 28, when merchants at Tehran’s Grand Bazaar closed their shops over the Iranian rial’s plummeting value. The demonstrations quickly spread nationwide, with grievances evolving from concerns over soaring living costs to broader opposition against Iran’s clerical establishment, who have governed the country since the Islamic Revolution in 1979.

According to Iranian state media, at least 109 security personnel have been killed in the unrest, but opposition activists based outside the country say the death toll is higher and includes hundreds of protesters.

A nationwide internet blackout has also persisted for more than 72 hours, according to monitoring groups.

Iran’s President Masoud Pezeshkian said on Sunday that his government was “ready to listen to” protesters, but urged the public to prevent “rioters” and “terrorist elements” from wreaking havoc.

The unrest in Iran is unfolding as Trump pursues an assertive foreign policy, having abducted Venezuelan President Nicolas Maduro, and discussing acquiring Greenland by purchase or force.