Iran’s Supreme Leader Ayatollah Ali Khamenei on Saturday branded U.S. President Donald Trump a “criminal” for supporting protesters in Iran and blamed demonstrators for causing thousands of deaths during weeks of unrest.

In a televised speech, Khamenei said the protests that began on Dec. 28 had left “several thousand” people dead, marking the first time an Iranian leader publicly acknowledged the scale of casualties from the crackdown. Human rights groups say at least 3,308 people have been killed, though the figure could not be independently verified.

Khamenei accused Trump of encouraging what he called “seditious” protesters and alleged the United States was seeking to dominate Iran politically and economically. He described demonstrators as “foot soldiers” of Washington and claimed they were responsible for violence, including attacks on mosques and educational centers.

Trump responded by sharply criticizing Iran’s leadership, calling Khamenei “a sick man” and urging an end to his nearly four-decade rule. He said Iran’s poor leadership had made it one of the worst places to live and called for new leadership in the country.

The exchange followed more conciliatory remarks by Trump a day earlier, when he said Iran had halted the execution of hundreds of protesters, though Iranian officials dismissed his comments as baseless.

Iran has largely returned to an uneasy calm after the crackdown, with no major protests reported in recent days. Authorities had cut internet access nationwide earlier this month, though limited services and text messaging briefly resumed in some areas on Saturday.

Iranian officials have repeatedly accused the United States and Israel of fueling the unrest, allegations both countries deny.