The Republican-controlled US Senate on Saturday rejected a Democratic attempt to pass legislation that would prevent President Donald Trump from taking military action against Iran without congressional approval.
The Senate voted 53 to 47 against the War Powers Resolution requiring congressional authorization.
The resolution, introduced by Senator Tim Kaine of Virginia, sought to reaffirm the need for Trump to obtain Congress's permission before engaging militarily with Iran.
Kaine long pushed to restore Congress's constitutional authority to declare war, challenging presidents from both parties.
Opponents of the resolution argued there was no need to limit the president's powers, viewing the strike on Iran as a limited, one-time operation within Trump's authority as commander-in-chief, not the start of ongoing military actions.
Several lawmakers are demanding more information about last week's US airstrikes targeting three nuclear facilities in Iran.