The United States has suspended all nonlethal assistance for the opposition in northern Syria.
A U.S. Embassy spokesman in Ankara said on December 11 that the move came after Islamist rebel forces moved against the Western-backed Free Syrian Army (FSA).
Fighters from the Islamic Front, a union of six major rebel groups, took control of FSA bases at the Bab al-Hawa crossing on Syria's northwestern border with Turkey late on December 6.
The seizure came after the Islamic Front announced that it rejected the authority of the FSA command.
The Islamic Front was formed last month when six groups merged and pledged to work toward forming an Islamic state.
The Islamic Front does not include Al-Qaeda affiliates like the Islamic State in Iraq and the Levant and the Al-Nusra Front.
The rebel infighting comes as Syrian government forces are making advances.
Based on reporting by AFP and Reuters