US President Barack Obama battled for congressional authorisation to bomb Syria, as two top republicans warned of a "no" vote if Obama's plan is not limited.
Hawkish senators John McCain and Lindsey Graham on Monday emerged from an hour of talks with Obama and suggested the White House could be mulling a wider military campaign in Syria than first thought.
Obama shocked Washington on Saturday when he decided to seek support for military action from Congress, just when it seemed cruise missile strikes on President Bashar al-Assad's forces and assets were imminent.
Obama has stressed that any US action would be "limited" and "narrow".
Al Jazeera's Patty Culhane reports from Washington D.C.