Sen. Angus King, I-Maine, indicated Monday that he will likely vote in favor of a war powers resolution aimed at curbing President Donald Trump’s military action in Iran.

It’s unclear whether King’s colleague, Sen. Susan Collins, R-Maine, will join him.

Over the weekend, the U.S. and Israel launched strikes against Iran that upended the Middle East. U.S.-Israeli air attacks killed Ayatollah Ali Khamenei, Iran’s longtime supreme leader. The strikes came amid indirect negotiations over Iran’s nuclear program and after months of nationwide economic protests that the Iranian regime had responded to with deadly crackdowns on demonstrators.

Iran responded by launching strikes of its own against Israel and various Arab neighbors. At least six U.S. service members, around a dozen Israelis and hundreds of Iranians have been killed so far in the war. Trump said Monday that the conflict was the “last best chance” to halt the threat posed by Iran’s nuclear program, and suggested the U.S. campaign may last at least four to five weeks.

Congress is set to vote later this week on a bipartisan war powers resolution that aims to limit Trump’s actions in Iran. But as with a Venezuela-focused resolution in January, this one is coming after the Republican president has already authorized military strikes without consulting lawmakers.

King, an independent who caucuses with Democrats and who is on the Senate’s intelligence and armed services committees, told reporters Monday that he is expecting to receive a classified briefing Tuesday from Trump administration officials on the Iran operation. Floor votes on the resolution may happen either Wednesday or Thursday.

King said he’s a likely “yes,” though he wants to hear what officials say in Tuesday’s briefing.

“I start out skeptical, because the arguments for doing this in the first place seem to be falling apart,” King said of the Trump administration’s explanations for the Iran strikes. “… Why are we doing this? Why didn’t you come to the American people in the first place? And finally, what is the game plan from here on out, and does it involve further engagement of American military personnel?”

The Trump administration’s reasons for engaging in the conflict have shifted since it began over the weekend. Initially, the president encouraged the people of Iran to “take back” the government from its current leaders. By Monday, Secretary of Defense Pete Hegseth said the goal was not to topple Iran’s government.

“This is not a so-called regime change war, but the regime sure did change,” Hegseth said at a news conference.

In the Republican-controlled Congress, any effort to rein in the president’s war powers could struggle to overcome a Trump veto. A veto override requires the support of at least two-thirds of lawmakers.

Collins is waiting for the classified briefing to make a decision on the latest war powers resolution, spokesperson Blake Kernen said Monday.

Collins had said in a brief statement Saturday that “sustained combat operations require full engagement with Congress,” while bashing the “Iranian regime’s pursuit of nuclear weapons, ballistic missile development and support for terrorist proxies.”

King and Collins, the lone Republican in Maine’s congressional delegation, each voted to advance the January war powers resolution that reaffirmed the need for congressional approval for future military actions in Venezuela. That vote came after Trump had approved an operation to nab former Venezuelan leader Nicolas Maduro for prosecution in the U.S.

Still, Collins had helped defeat a resolution last November to limit Trump’s ability to attack Venezuela.

Trump said upon winning a second White House term that he would “stop wars.” Hegseth declined Monday to rule out deploying American ground forces in Iran.