A Republican House member from Michigan openly mused during a town hall last week about wiping out Gaza, telling his constituents that “it should be like Nagasaki and Hiroshima.”

“Get it over quick,” Representative Tim Walberg said, according to a video that emerged online from the March 25 event in Dundee, Mich.

His remarks, invoking the U.S. atomic bombings of Japan during World War II while discussing his opposition to U.S. humanitarian aid for Gaza, drew swift condemnation, including at least one call for his resignation. He said that his remarks were taken out of context and that the clip showed only part of his response.

Justin Amash, a former House G.O.P. colleague in Michigan and a Palestinian American, denounced Mr. Walberg for his comments, writing on X on Saturday that they “evince an utter indifference to human suffering.

“The people of Gaza are our fellow human beings — many of them children trapped in horrific circumstances beyond their individual control,” Mr. Amash wrote. “For him to suggest that hundreds of thousands of innocent Palestinians should be obliterated, including my own relatives sheltering at an Orthodox Christian church, is reprehensible and indefensible.”

Mr. Amash, the only sitting Republican member of Congress to support President Trump’s first impeachment, left the Republican Party in 2019 while facing attacks by Mr. Trump. Mr. Amash is running in the Republican primary for U.S. Senate in Michigan.

In a post on X on Sunday morning, Mr. Walberg, 72, a former pastor and a longtime House member who represents southern Michigan, sought to clean up his remarks and accused his critics of twisting his words.

“As a child who grew up in the Cold War Era, the last thing I’d advocate for would be the use of nuclear weapons,” he wrote. “In a shortened clip, I used a metaphor to convey the need for both Israel and Ukraine to win their wars as swiftly as possible, without putting American troops in harm’s way.”

Mr. Walberg’s office also provided an audio recording and a transcript of the exchange that prompted his remarks. He had been asked why the United States was spending money to build a pier to deliver humanitarian aid to Gaza.

“We shouldn’t be spending a dime on humanitarian aid,” he said, according to the recording. “It should be like Nagasaki and Hiroshima. Get it over quick. The same should be in Ukraine. Defeat Putin quick. Instead of 80 percent of our funding for Ukraine being used for humanitarian purposes, it should be 80 percent, 100 percent to wipe out Russian forces, if that’s what we want to do.”