Republican presidential hopeful Donald Trump has sparked anger by attacking the military record of Senator John McCain, a former prisoner of war.
The billionaire and reality TV star said Mr McCain was only considered a hero because he was a prisoner of war.
He then added: "I like people who weren't captured."
The comments prompted strong criticism across the party. Rival contender Rick Perry said the remarks were a "new low" in US politics.
A good time to re-read Matt Labash's 1999 classic,"A Chump On the Stump: Donald Trump pretends to run for President." http://t.co/S416QDRCwU— Bill Kristol (@BillKristol) July 18, 2015
Mr Trump later sought to clarify his remarks, although did not apologise.
"If a person is captured, they're a hero as far as I'm concerned," he said. "I don't like the job John McCain is doing in the Senate because he is not taking care of our veterans.''
The two have clashed before, with Mr McCain accusing Mr Trump of having "fired up the crazies" with his attacks on Mexican immigrants.
Mr McCain was held for five-and-a-half years after his plane was shot down in the Vietnam war. Mr Trump avoided service through student and medical deferments.
The 2008 presidential candidate is yet to respond to Mr Trump's remarks, although his daughter Meghan tweeted she was "disgusted".