Donald Trump on Sunday stood by incendiary remarks in which he mocked Senator John McCain over his capture during the Vietnam war, refusing to bow to a chorus of criticism from Republicans and insisting he has no plans to pull out of the party's presidential nomination contest.

Is this guy serious? Could Republican frontrunner Trump actually win?

Read more

The outspoken business mogul, who leads a crowded field of Republican presidential contenders in several recent polls, sparked widespread condemnation on Saturday after declaring in Iowa that McCain, who was tortured during more than five years as a prisoner of war, was "not a war hero".

Less than 24 hours later, after a furious and virtually unified response from his rivals, Trump insisted that his comments about McCain were "absolutely fine". He argued he was the victim of a controversy stoked by the press and Republican adversaries envious of his surge in popularity.

In his first media appearance since the comments, which he made at a gathering of social conservatives in Ames, Iowa, Trump was asked on ABC if he would apologise.

"No, not at all," he replied. "When I left the room it was a total standing ovation, it was wonderful to see, nobody was insulted."

The remarks appear to have marked a turning point in the Republican race, prompting the party establishment, which previously resisted condemning Trump's offensive remarks about Mexican immigrants, to finally come out against the billionaire TV celebrity en masse.

Trump, in return, was defiant.

"I will say what I want to say," he told ABC. "And maybe that's why I am leading in the polls. Because people are tired of hearing politicians, and pollsters telling the politicians exactly what to say."

During the 10-minute interview, conducted over the phone, the billionaire property developer did appear to waver a little, saying his remarks about McCain had somehow been misconstrued.