The U.S. Treasury Department said that Ahrar al-Sharqiya had committed multiple crimes against civilians, especially Syrian Kurds, including unlawful killings, "abductions, torture, and seizures of private property."
It said that it was blocking any assets and banning any US transactions with the armed group.
"Our designations today should serve as a reminder that the United States will use all its diplomatic tools to promote accountability of persons who have inflicted abuses and suffering against the Syrian people," said Aimee Cutrona, a senior U.S. State Department official handling Syria.
The UN rights office said that fighters from the group pulled a 35-year-old Syrian Kurdish politician, Hevrin Khalaf, out of her car and shot her dead in a possible war crime.
Khalaf was the secretary-general of the Future Syria Party in October 2019 during Turkey’s military operation into Syria.
The U.S. Treasury Department also said that it imposed sanctions on eight prisons run by Syria's intelligence apparatus and on five Syrian officials who directed the prisons.
"Many of the prisons designated today were highlighted in the pictures provided by Caesar, a Syrian regime defector who worked as an official photographer for the Syrian military and exposed the regime’s ruthless and cruel treatment of detainees," U.S. Secretary of State Antony Blinken said in the statement.
In a separate statement, the Treasury said it had imposed sanctions on Hasan al-Shaban, an alleged Al-Qaeda fund-raiser based in Turkey and Farrukh Furkatovitch Fayzimatov from Tajikistan, who is accused of funding the Hayat Tahrir al-Sham alliance.
Beyond blocking their assets and barring U.S. persons from dealing with them, these sanctions threaten non-U.S. persons with losing access to the U.S. market if they deal with the two.
Reporter's code: 50101