Sen. Susan Collins voted against a measure to advance a war powers resolution Wednesday that would have forced President Donald Trump to receive congressional approval before launching more attacks against Iran, siding with the Republican-controlled Senate to defeat the symbolic measure.

The Senate voted 53-47 to defeat a “discharge” motion to move the resolution to the floor for debate. Collins, the lone Republican in Maine’s congressional delegation, and Sen. Angus King, an independent who caucuses with Democrats, voted with their respective caucuses. Sen. Rand Paul of Kentucky was the only Republican to support the measure, while Sen. John Fetterman of Pennsylvania was the only Democrat to oppose it.

The House may take up similar resolutions later this week.

The attempt to curb Trump’s military action was always likely to face a veto from the Republican president. Over the weekend, Trump signed off on U.S.-Israeli strikes that killed Ayatollah Ali Khamenei, Iran’s longtime ruler, and ignited a new war featuring a wave of retaliatory strikes across the Middle East from Iran and its proxies.

A rising death count included six U.S. soldiers and at least 1,000 civilians in Iran as of Wednesday afternoon.

In a statement on the vote Wednesday, Collins emphasized that Iran poses a threat to the United States and its allies, and that “we cannot tolerate a nuclear-armed Iran.” In addition to its nuclear program, Collins cited the country’s support of terrorist organizations and development of ballistic missiles.

“The Constitution gives Congress an essential role in matters of war and peace,” Collins said. “Sustained combat operations require full engagement with Congress. The Administration has adhered to the provisions of the War Powers Act that require notification to Congress within 48 hours of hostilities commencing, and it has provided numerous classified briefings to Congress.”

She also said that the resolution “would send the wrong message” to both American troops and Iran.

“At this juncture, providing unequivocal support to our service members is critically important, as is ongoing consultation by the Administration with Congress,” Collins said.

King said that he has “no sympathy whatsoever for the Iranian regime,” but, while the president has the power to protect the country from an imminent threat, the power to wage war lies in the hands of Congress.

“What bothers me about where we are, and the reason I voted yes today, is that going to war is the most solemn step that any country can make,” King said. “The framers of our Constitution knew that.”

Trump has not ruled out deploying U.S. ground troops to the conflict. He said he is hoping to end the bombing campaign within a few weeks, but Defense Secretary Pete Hegseth said Wednesday the war could drag on longer. Trump’s goals for the war have shifted from regime change to stopping Iran from developing nuclear capabilities to wiping out its navy and missile programs.

King said Trump ought to be forthcoming about whether ground troops will be deployed.

“If that’s going to be the case, the president should tell us that,” he said. “That’s one of the costs of war and the American people should know what they’re committing to.”

Collins, who is up for reelection to a sixth term this year, had opted not to reveal her stance ahead of Wednesday on the resolution from Sen. Tim Kaine, D-Virginia. King indicated earlier this week he would likely support the resolution and said he felt the Trump administration’s reasons for the war “seem to be falling apart.”

Last week, Collins had said Trump should only strike Iran as a “last resort” amid tense negotiations over a nuclear deal. After the U.S. and Israel launched initial strikes Saturday, Collins said in a statement that did not mention Trump by name that “sustained combat operations require full engagement with Congress.” She also bashed the “Iranian regime’s pursuit of nuclear weapons, ballistic missile development and support for terrorist proxies.”

Last November, Collins had helped defeat a resolution to limit Trump’s ability to attack Venezuela. Then came a swift U.S. operation in January to nab former Venezuela leader Nicolas Maduro. Collins and King responded to that by voting in favor of a war powers resolution meant to reaffirm the need for congressional approval on future military actions in Venezuela.

Trump did not take kindly to Collins’ vote on Venezuela, posting on social media in response that she “should never be elected to office again.”

Polling released ahead of Wednesday’s vote showed 58% of Mainers opposed the U.S. attacks on Iran. The latest University of New Hampshire poll revealed a partisan divide on the war, with 98% of Maine Democrats saying Trump should have first asked for congressional approval and 76% of Maine Republicans responding that Trump should not have asked for approval.