The department said it designated Maysar Ali Musa Abdallah al-Juburi and Anas Hasan Khattab as senior leaders of al-Nusra Front, an entity the U.S. State Department said is an alias for al-Qaida in Iraq. The Treasury Department said its actions were part of an effort to support the Syrian people as they try to break free from Syrian President Bashar Assad.
"We will target the pro-Assad militias just as we will the terrorists who falsely cloak themselves in the flag of the legitimate opposition," Undersecretary for Terrorism and Financial Intelligence David Cohen said in a statement.
Cohen said al-Nusrah Front was likely tied to as many as 600 terrorist attacks in Syria since last year. The Shabiha militia, said to be "instrumental" in the Syrian government's "campaign of terror," was also targeted by U.S. sanctions.
The civil war in Syria is descending on the nation's capital as support for a formal opposition council grows. Victoria Nuland, a spokeswoman for the State Department, said terrorist ideology has no place in a future Syria.
"The sooner the political transition to a post-Assad Syria begins, the better it will be for the Syrian people and the region," she added.