WASHINGTON -- The House overwhelmingly passed a resolution Friday that would bar President Barack Obama from sending forces to Iraq in a "sustained combat role" without congressional approval. The bill is likely to have greater symbolic than legal effect.

The nonbinding measure hasn't been debated in the Senate. Its language opens up several questions related to the U.S. Constitution's separation of powers between executive and legislative branches, even if Obama and his top military advisers already have ruled out sending combat troops to help Iraq fight extremist insurgents.

Friday's legislation was approved by a 370-40 vote after Republican and Democratic lawmakers emphasized the need to reassert what they argued is their constitutional control over authorizing military force.

"This resolution makes one clear statement," said its sponsor, Rep. Jim McGovern, a Democrat. "If the president decides we should further involve our military in Iraq, he needs to work with Congress to authorize it."

"The time to debate our re-engagement in Iraq, should it come to that, is before we are caught in the heat of the moment," he said. "Not when the first body bags come home. Not when the first bombs start to fall. Not when the worst-case scenario is playing out on our TV screens."

More than 800 U.S. forces are in Iraq. More than half are providing security for the embassy and U.S. personnel. American service members also are involved in improving U.S. intelligence, providing security co-operation and conducting assessments of Iraqi capabilities.

U.S. officials say the Sunni extremists who call themselves the Islamic State pose a significant threat to the American homeland. The group has expanded from its base in Syria and seized a series of towns and cities in Iraq in recent months.