US election 2016: Carson says Obama was 'raised white'
Barack Obama was "raised white", Republican presidential candidate Ben Carson has claimed.
Mr Carson said the president could not understand the African-American experience the way he could.
Mr Obama was born to a white American mother and a black Kenyan father. Mr Carson's parents are African-American.
The comments by Mr Carson - a retired neurosurgeon who finished last in South Carolina's primary - were criticised as "loose talk" by another Republican.
"He's an 'African' American. He was, you know, raised white," Mr Carson told a Politico podcast on Tuesday.
"Many of his formative years were spent in Indonesia. So, for him to, you know, claim that, you know, he identifies with the experience of black Americans, I think, is a bit of a stretch."
Mr Carson, who at one point was pushing businessman Donald Trump near the top of the polls, said he was proud "we broke the colour barrier" when Mr Obama became the first black president in 2008.
"But I also recognise that his experience and my experience are night-and-day different. He didn't grow up like I grew up by any stretch of the imagination," he said.
The 64-year-old had a poor upbringing in Detroit but made it to Yale before a brilliant career as a neurosurgeon.
But he has been struggling in the Republican nomination race and finished sixth out of six in South Carolina at the weekend.
On the Carson campaign trail - BBC's Anthony Zurcher, Las Vegas
While Mr Trump's nearby rally drew a who's who of the national press corp, Mr Carson's event was largely ignored.
The Secret Service still stands watch over the proceedings, but the screening of elderly retirees with their walkers and artificial hips seemed a bit absurd.
After the event, however, many of the attendees said the retired neurosurgeon had won their support.
"I thought his speech was inspiring, logical and it made sense," said Marty Glazman. "He had a thought-out plan. I came in with an open mind, but I can honestly say I'm now a supporter."
Mr Obama has not publicly responded to Mr Carson's comments.
But Republican Congressman Darrell Issa, who backs Senator Marco Rubio in the Republican race, criticised Mr Carson.
"This is the reason that political loose talk by people who are just beginning to do it is always a problem in real statesmanship," Mr Issa told CNN.
"The fact is that Dr Carson is not really ready to represent America around the world," he added.
On Tuesday, Republican voters in Nevada will make their choice for president.