Senate Republicans have blocked a vote on a $625 billion defense bill after Democrats tried to limit amendments.
The vote was 51-44, nine short of the necessary votes to move ahead. The vote leaves the measure setting military pay and policy in limbo with a few legislative days remaining for the Senate to act and reconcile its version with the House.
Republicans had pressed for votes on amendments dealing with Iran, Egypt and other issues, arguing that a measure authorizing more than $600 billion for personnel, weapons, ships and aircraft deserved extensive deliberations.
Senate Majority Leader Harry Reid had pushed to wrap up the bill before the Senate's two-week Thanksgiving break.
The Senate voted on just two amendments dealing with the detention center at Guantanamo Bay, Cuba.