The US House of Representatives on Thursday approved a resolution seeking to limit President Donald Trump's authority to wage war against Iran, with four Republicans joining Democrats in a bipartisan vote.
The measure passed 214-208, days after renewed fighting between the United States and Iran intensified following the collapse of a ceasefire.
The resolution seeks to require congressional authorisation for further military action against Iran, reflecting growing concern among lawmakers over the expanding conflict.
The US Senate was also expected to vote on a similar War Powers Resolution, although the measure is largely viewed as symbolic.
Congress seeks to reassert authority
Supporters of the resolution argued that under the US Constitution, only Congress has the authority to declare war.
Representative Pramila Jayapal said lawmakers had a responsibility to reassert Congress' constitutional role over decisions involving military action.
"This war must end," she said during debate on the House floor.
Although Congress previously approved a similar resolution in June, it was passed as a concurrent resolution and was not sent to the president for approval.
Even if approved as a joint resolution, Trump could veto the measure, requiring a two-thirds majority in both chambers to override it.
Renewed fighting
The vote comes after hostilities between Washington and Tehran resumed following the breakdown of a temporary ceasefire earlier this month.
The Trump administration has argued that Iran poses an imminent threat to US national security, justifying continued military action, while critics contend the conflict requires explicit congressional authorisation under the 1973 War Powers Act.
Legal experts have also questioned the administration's interpretation of the law, arguing that the prolonged conflict exceeds the constitutional limits on unilateral military action.
The House vote follows approval earlier this week of a $1.15 trillion defence spending bill, which includes additional funding related to the conflict.
