Iran reportedly issued its first death sentence linked to the uprising following the death of a young woman who was in police custody.
According to CNN, the protester was sentenced to death for allegedly setting fire to a government building.
The White House condemned the reported punishment, saying the world is watching what's happening in Iran.
"The United States, standing with our partners and allies around the world, will continue to pursue accountability for those responsible for these abuses through sanctions and other means," said National Security Advisor Jake Sullivan.
Protests in Iran began in September after the death of 22-year-old Mahsa Amini. She was detained by the country's “morality police,” which was reportedly enforcing Iran's hijab law. The law requires women to cover their hair.
Iranian authorities reportedly claimed Amini suffered a heart attack. They also pushed back on claims that Amini was beaten while in custody.
Iran Human Rights, a nonprofit organization, claims Iranian security forces have killed hundreds of protesters. The death toll includes women and children.