WASHINGTON — The U.S. Senate on Wednesday rejected a Democratic resolution that would have limited President Trump's authority to use military force against Iran. A motion to discharge the measure from committee failed by a vote of 49 to 50.

Senators Rand Paul of Kentucky, Susan Collins of Maine, and Lisa Murkowski of Alaska voted in favor of advancing the measure, while Senator John Fetterman of Pennsylvania was the sole Democrat to oppose it. Until this sixth attempt by Senate Democrats since the war began on February 28, Paul had been the only Republican to support advancing such resolutions.

The resolution, led by Senator Jeff Merkley of Oregon, would have directed the president to remove U.S. Armed Forces from hostilities within or against Iran unless explicitly authorized by a declaration of war or a specific authorization for use of military force. Senator Jim Risch, chairman of the Senate Foreign Relations Committee, said that the hostilities referenced in the War Powers Resolution "do not exist today and have not existed for some time."

The War Powers Resolution of 1973 requires the president to report to Congress within 48 hours of deploying forces if Congress has not authorized a declaration of war and limits any unauthorized engagement to 60 days. The administration has argued that the resolution does not apply because the 60-day clock stopped with the ceasefire reached on April 7.

Merkley said he does not accept that the 60-day clock is suspended. "The war is at a different stage, and it may heat up again," he said. He said two factors may have influenced Republican senators: giving credit to the ceasefire and the president being overseas in China. Merkley said he saw "erosion of support, erosion of enthusiasm, an increase in skepticism among our Republican colleagues about this whole operation." He also said many Republicans "are uncomfortable with where they stand, but they're also uncomfortable with being on the wrong side of Trump."

Murkowski had voted against advancing previous iterations of the measure. She said she had expected to receive more clarity from the administration after the 60-day window passed but had not received it, and that she felt it was time to support the measure so lawmakers could discuss their responsibilities under the War Powers Resolution. Murkowski has said she intends to introduce a formal authorization for the use of military force in Iran. At a hearing on Tuesday, she questioned Defense Secretary Pete Hegseth about the administration's authority and asked whether clarifying the president's authority through congressional approval would be helpful to the president.