The United States President Barack Obama said, while urging Arab nations to support the airstrikes on Islamic State (IS) in Iraq and Syria, that it was 'not America's fight alone'.
He spoke after the U.S. and Arab countries launched their first airstrike against IS fighters in Syria, reported the BBC.
Activists said that more than 70 IS militants and 50 al Qaeda fighters were killed in the airstrikes.
US state department spokeswoman Jan Psaki said that the U.S. had earlier warned Syria not to 'engage U.S. aircraft.
She also said that Washington had not given a notice of the attack timing.
The U.S. officials have released a video footage of the attacks that were launched on Monday.