Republican presidential candidate Ben Carson has said he would not support a Muslim candidate for the President of the United States.

In an interview with NBC yesterday, Carson said "I would not advocate that we put a Muslim in charge of this nation. I absolutely would not agree with that."

The 7-day-adventist did say he would be happy to vote for a Muslim in congress, depending on his policies.

Carson, a former neurosurgeon, is second to Donald Trump in the Republican presidential race.

His interview with NBC focused around the controversy that arose when Trump failed to correct an audience member at a campaign rally who claimed President Obama was a Muslim.

The audience member said, "We have a problem in this country; it's called Muslims," which Trump did not protest.

Trump sought to defend himself on Twitter, saying "Am I morally obligated to defend the president every time somebody says something bad or controversial about him? I don't think so!"

Carson has said he had no reason to question that Obama is a Christian.

When asked more broadly whether a president's faith should matter to voters he said, "I guess it depends on what the faith is. If it's inconsistent with the values and principles of America, then of course it should matter. But if it fits within the realm of America and consistent with the Constitution, no problem."

Carson said he would not support a Muslim president because he did not believe that Islam is consistent with the constitution.

He did say that he would be open to voting for a Muslim for congress.

"Congress is a different story, but it depends on who that Muslim is and what their policies are, just like it depends on what anybody else is," Carson said. "If there's somebody who is of any faith but they say things and their life has been consistent with things that will elevate this nation and make it possible for everybody to succeed and bring peace and harmony, then I'm with them."

There are currently two Muslim members of congress. Keith Ellison, the first Muslim elected to Congress, released a statement in response to Carson's comments.

"For Ben Carson, Donald Trump, or any other Republican politician to suggest that someone of any faith is unfit for office is out of touch with who we are as a people," he said.

"It's unimaginable that the leading GOP presidential candidates are resorting to fear mongering to benefit their campaigns, and every American should be disturbed that these national figures are engaging in and tolerating blatant acts of religious bigotry."

Democratic candiate Bernie Sanders has also reacted to Carson's position:

"You know, this is the year 2015. You judge candidates for president not on their religion, not on the colour of their skin, but on their ideas, on what they stand for."