Lisa Murkowski

The U.S. Senate approved an important but largely symbolic war powers resolution on Tuesday calling on President Donald Trump to remove U.S. armed forces from Iran.

Sen. Lisa Murkowski was one of four Republican senators to join most Democrats in support. Republican Sens. Susan Collins of Maine, Rand Paul of Kentucky and Bill Cassidy of Louisiana also voted for the measure, which passed 50-48.

Sen. Dan Sullivan voted against it, joining most other Republican senators and aligning himself with Trump.

On Tuesday, staff with the senators’ offices referred to past statements they’ve made to describe their position.

This vote, and the House of Representatives’ approval of the same resolution earlier this month, represents a major split between Trump and the Republican-controlled Congress in his second term. The move by the Senate to approve the war powers resolution comes days after the Trump administration announced it had signed a memorandum of understanding to end the war with Iran, launching peace talks between the two countries.

The Senate had unsuccessfully tried to advance a war powers resolution involving the Iran war on nine previous occasions. It passed Tuesday when Republican Sens. Mitch McConnell of Kentucky and Dave McCormick of Pennsylvania were absent.

The resolution likely doesn’t carry the force of law but reflects the sentiment of Congress as the war nears its fifth month. The vote marks the first time that both chambers of Congress have approved a concurrent resolution instructing a president to end a military action since the War Powers Resolution of 1973 was enacted, the BBC reported.

Murkowski had initially voted no on the resolution, believing that an abrupt withdrawal could endanger U.S. troops and civilians, and that Trump was operating within his constitutional authority under the 60-day threshold established by the War Powers Act, she has said.

But Murkowski switched her position in May, and began voting for the resolution. That’s because the 60-day limit for hostilities without congressional authorization had passed, she said. Also, the administration asserted that hostilities had ended, removing any justification for keeping U.S. service members in harm’s way without congressional authorization, she said last month.

Joe Plesha, her spokesperson, said Tuesday that Murkowski’s position hasn’t changed since she began supporting the measure, and he declined to offer a new statement.

Sullivan’s office said Tuesday that he has supported giving presidents from both parties authority under the U.S. Constitution to protect U.S. security interests.

“Iran has been at war with the United States for nearly 50 years,” his office said in a statement provided by spokesperson Amanda Coyne. “They have killed and wounded thousands of America’s best and brightest. Every president since the Iranian Revolution has focused on making sure Iran — the world’s largest state sponsor of terrorism — doesn’t have nuclear weapons and ballistic missiles.”

Rep. Nick Begich also voted against the measure earlier this month. He did not reply to a request for comment Tuesday.

He has previously called the war, which began in February, “a necessary and targeted response.”