ERBIL, Kurdistan Region of Iraq – US Senator Lindsey Graham, a longtime critic of the Islamic regime in Iran, on Monday urged President Donald Trump to take “decisive military action” against the country and its leadership, citing the Tehran government’s violent crackdown on protesters.

Mass anti-government demonstrations have engulfed Iran in recent weeks, prompting a heavy response from Iranian authorities, with over 650 protesters killed so far, according to confirmed figures by rights watchdogs, while the actual toll is feared to be much higher.

“I believe the Iranian regime has crossed red lines. They are killing their people in large numbers and mocking your [Trump’s] leadership. It is now time to take decisive military action — no boots on the ground – going after those who do the killing,” Graham wrote in a message addressed to Trump on X.

Even Iran’s most conservative cities, Mashhad and Qom, have taken part in the recent strikes and demonstrations, amid the country’s collapsing economy.

Graham ascribed the scale of the recent demonstrations to the American president’s repeated threats that Washington will intervene if Tehran kills protestors.

“Your [Trump’s] promise to have the protestors’ back and put the regime on notice that you will not tolerate the killing has led to the largest outpouring of demonstrators against this fanatical regime since its founding.”

White House Press Secretary Karoline Leavitt on Monday said the American president would prefer a diplomatic route with Iran, but stressed that Trump would not shy away from “military options” if Tehran does not cease its heavy crackdown on peaceful protesters, as he has repeatedly threatened.

Iranian authorities have dismissed Trump’s threats, with Parliament Speaker Mohammad Bagher Ghalibaf recently warning that the US and Israel would be “legitimate targets” should Washington intervene militarily.

However, Leavitt asserted that public statements made by Iran are “quite different” from what Washington receives privately, noting that Iranian officials have reached out to Washington and discussed the possibility of engaging in negotiations.

Nationwide demonstrations in Iran began on December 27 at Tehran’s Grand Bazaar, where business owners and shopkeepers launched strikes and protests over the falling value of the Iranian rial against the US dollar.

The demonstrations later spread to other provinces, with chants increasingly targeting the state amid a surging current of anti-government sentiment.

The Norway-based Iran Human Rights on Monday reported that at least 648 protesters have been killed and thousands have been injured in 16 days of protests, with more 10,000 arrested.

The watchdog noted that some reports estimate more than 6,000 may have been killed, but that remains difficult to verify as Iranian authorities have imposed a nationwide internet blackout since January 8, severely restricting access to information.

In a televised interview with Fox News on Sunday, Graham stated: “If I were you, Mr. President, I would kill the leadership that are killing the people. You’ve got to end this.”