Louisiana Senator Bill Cassidy joined three other Republican lawmakers in supporting the measure. Though symbolic and unlikely to become law, advancing the resolution is a sign of growing frustration with the war.
The US Senate on Tuesday voted to advance a measure to force President Donald Trump to withdraw the US from hostilities in Iran or seek congressional approval to continue with military action.
A procedural vote on awar powers resolution has been held seven times since Trump launched the war against Iran in late February. But the Democratic-led effort has been quashed by Republicans each time.
This was the first time the legislation was advanced in the chamber, which means that there is now going to be a final vote on the resolution in the coming weeks.
But Tuesday's vote is procedural and faces steep hurdles before going into effect.
