The State Department called for Hezbollah fighters to leave Syria Wednesday amid growing reports of the Islamic group's participation in the civil war.
Spokesperson Jen Psaki told reporters that the State Department's demand comes as a response to Hezbollah's recent vow for victory in Syria.
In a televised statement Saturday, Hassan Nasrallah, the leader of the Lebanese Shia militant Hezbollah movement, claimed to work for President Assad's forces and would not allow the Sunni rebels to win the civil war in Syria.
Secretary of State John Kerry has recognized Hezbollah's involvement in Syria and said that Iran is supporting the militant group.
Psaki was also questioned about the state department's slow response to evidence of chemical weapons being used in Syria, an act that the Obama administration deemed would cross a redline that would be followed by further American intervention in the civil war.
The State Department continues to wait for firm evidence of chemical use against the Syrian rebels, despite more reports from US allies that confirm chemical use. Psaki would also not give a timeline on when the State Department plans to release it's assessment of chemical weapon attack claims.
It was reported Tuesday that President Obama has asked the Pentagon to draw up plans for a no-fly zone in Syria. That report was later denied by Pentagon officials.
According to recent estimates by the United Nations, at least 80,000 people have died since the Syrian civil war started two years ago.