Republican presidential frontrunner Donald Trump has said he was not morally obligated to defend US President Barack Obama after he let pass unchallenged a questioner's assertion that the US leader is a Muslim.
In a rapid-fire series of tweets on Saturday, the billionaire real estate mogul responded to a barrage of criticism of his handling of the incident, which came from Democrats and one fellow Republican candidate, New Jersey Governor Chris Christie.
"Am I morally obligated to defend the president every time somebody says something bad or controversial about him? I don't think so!" Trump said.
Trump, who helped fuel a "birther" movement in 2011 by repeatedly demanding Obama prove he was not born in Kenya, appeared to encourage a man at a campaign stop in New Hampshire on Thursday after he made the incorrect assertion about Obama's faith.
"We have a problem in this country, it's called Muslims. We know our current president is one, you know he's not even an American," the unidentified questioner said.
Trump chuckled and interrupted him to say, "We need this question. This is the first question."