President Joe Biden called on Iran to “end the violence against its own citizens,” in response to a deadly crackdown by security forces on protests in the country.

“We stand with the citizens and brave women of Iran,” Biden said Friday at the start of a speech in Irvine, California, on cutting health care costs. Biden acknowledged the presence of people in the crowd, some of whom wore shirts that said “Free Iran.”

Iran has been gripped by protests that broke out in early September after 22-year-old Mahsa Amini died in police custody. She had been arrested for allegedly violating the country’s strict Islamic dress codes.

“Women or men should have the right to freedom of expression and assembly,” said Biden. “Women all over the world are being persecuted in various ways. But they should be able to wear in God’s name what they want to wear, no one should be telling them what to wear.”

The ongoing unrest is one of the biggest challenges to the Islamic Republic since its founding after the 1979 revolution and officials have sought to crack down on the demonstrations.

Oslo-based Iran Human Rights, a group monitoring the protests, said Wednesday it had confirmed the deaths of at least 201 people since Sept. 16.

The Biden administration has sanctioned Iranian officials it said played a role in the crackdown and in cutting off internet access, along with Iran’s Morality Police.

“It stunned me what it awakened in Iran,” Biden said Friday about Amini’s death and the protests. “It’s awakened something that I don’t think will be quieted in a long, long time.”