Sen. John McCain said Wednesday that the Senate’s annual defense policy bill was being held up on the chamber floor due to a disagreement over four proposed amendments.

The impasse might lead to Senate Majority Leader Mitch McConnell invoking cloture, a procedural move that could delay the National Defense Authorization Act for days and quash expected debate on those four amendments and others filed in recent weeks, McCain, R-Ariz., the Armed Services Committee chairman, said on the Senate floor.