President Donald Trump on Saturday called for an end to Ayatollah Ali Khamenei’s 37-year reign.

“It’s time to look for new leadership in Iran,” Trump told POLITICO, as widespread protests calling for an end to the regime appear to have waned.

Thousands of protesters across the country were killed over the last three weeks, prompting Trump to repeatedly threaten military intervention. On Tuesday, Trump called on Iranians to keep protesting and “take over institutions,” saying that “help is on its way.”

The next day, the president abruptly changed course, saying he had been informed that the killings had stopped.

“The best decision he ever made was not hanging more than 800 people two days ago,” Trump said Saturday, when asked about the size of a possible U.S. military operation in Iran.

Trump’s comments came shortly after Khamenei’s X account posted a series of hostile messages aimed at Trump, accusing the U.S. president of being responsible for deadly violence and unrest in Iran.

“We find the US President guilty due to the casualties, damages and slander he inflicted upon the Iranian nation,” Khamenei wrote.

In another post, he said Trump had mischaracterized violent groups as representing the Iranian people, calling it “an appalling slander.”

Trump, after being read the posts, said Tehran’s rulers rely on repression and violence to govern. “What he is guilty of, as the leader of a country, is the complete destruction of the country and the use of violence at levels never seen before,” Trump said. “In order to keep the country functioning — even though that function is a very low level — the leadership should focus on running his country properly, like I do with the United States, and not killing people by the thousands in order to keep control.”

“Leadership is about respect, not fear and death,” Trump added.

The exchange underscores a sharpening rhetoric between Washington and Tehran at a volatile moment for the region, and as Khamenei recently made a public address in which he claimed that “the Iranian nation has defeated America.”

Trump went further in personal terms, denouncing Khamenei and the Iranian system of governance.

“The man is a sick man who should run his country properly and stop killing people,” Trump said. “His country is the worst place to live anywhere in the world because of poor leadership.”