“With the negotiating window closed, sustained combat operations now require congressional authorization,” Nunn, an Air Force veteran, posted on social media. “I will not support another open-ended war.”

Nunn campaigned with Hegseth last month in Iowa, and the Pentagon chief had lauded Nunn as an ally who didn’t need any last-minute, late-night phone calls from Trump to persuade him to support the president’s agenda.

“Zach Nunn is not a 3 a.m. congressman,” Hegseth said at a fundraiser for Nunn during the Iowa State Fair. “He’s willing to take the tough votes to do the right thing on behalf of our war fighters.”

Nunn is up against Sarah Trone Garriott in November’s election.

Miller-Meeks, an Army veteran, said in a statement the president needs to present a plan to Congress and the public showing how the war ends so “we can focus on bringing our soldiers home and lowering prices.”

US Representative Mariannette Miller-Meeks (R-IA) was interviewed onstage at an Americans for Prosperity event at the Adventureland amusement park on Aug. 22, in Altoona, Iowa.Leon Neal/Getty

“Americans do not want another forever war,” she said. “I will not vote to keep our soldiers in an open-ended war, with Iowans paying too much at the pump.”

She faces a reelection rematch against Christina Bohannan, whom she has defeated twice before.

Eighteen U.S. service members have died in the war with Iran. Two are from Iowa, and one used to live in Iowa.

National polling indicates that the Iran war remains unpopular with Americans overall. Only about 3 in 10 U.S. adults approved of Trump’s handling of Iran in a July AP-NORC poll, and a September New York Times/Siena poll found that most likely voters, about 6 in 10, think Trump’s decision to go to war with Iran was the wrong one.

Tuesday’s House vote was the third time lawmakers voted to end the war in Iran. The margin was similar to earlier efforts, with a few more Republicans joining all Democrats in voting to bring an end to the conflict.

In addition to Nunn and Miller-Meeks, retiring Rep. Nancy Mace of South Carolina joined Republican Reps. Tom Barrett of Michigan, Warren Davidson of Ohio, Brian Fitzpatrick of Pennsylvania and Thomas Massie of Kentucky in voting for the resolution.

Rep. Ashley Hinson, who represents northeast Iowa but is running to replace retiring Sen. Joni Ernst, voted against the resolution.

Republicans have been optimistic that Iowa will remain a red state, but the competitive races have gotten attention even from the White House. Trump visited suburbs of Des Moines in January and dispatched Vice President JD Vance in May to campaign for Nunn.

After Hegseth campaigned with Nunn, a group of over 400 former national security officials filed a complaint asking for an investigation into whether the secretary violated the Hatch Act, which restricts political activities by federal officials.

Hegseth’s office did not immediately respond to a request for comment.