Trump (Reuters)

WASHINGTON — Republican Donald Trump finally acknowledged on Friday that President Barack Obama was born in the United States but accused Hillary Clinton of starting the so-called birther controversy, a charge that independent fact-checking sites have said is false.

“President Barack Obama was born in the United States. Period,” said Trump, reversing himself on a controversy about Obama’s birth that the Republican helped launch but that had become a distraction to his White House bid.

“Now we all want to get back to making America strong and great again,” he said at an event at a new hotel he owns in downtown Washington.

Without offering evidence, Trump accused Democratic rival Clinton of starting the birther allegations during her 2008 presidential primary campaign.

Trump had for years promoted the birther movement against Obama, who was born in Hawaii to an American mother and a Kenyan father. In 2012, The New York businessman wrote on Twitter that the president’s birth certificate was “a fraud.”

The birther conspiracies, which cast doubt over whether Obama is legally able to be president, incense black Americans whose votes Trump has been trying to court.

Clinton demanded Trump apologize to the president for having helped spread the birther idea and said Trump had tried to “delegitimize our first black president.”

“His campaign was founded on this outrageous lie. There is no erasing it in history,” Clinton said in an address to the Black Women’s Association in Washington.

The issue has not been a factor in the campaign for the Nov. 8 presidential election, but it resurfaced in recent days, taking the focus of Trump’s campaign away from topics such as immigration, trade and the economy, which he has been using to hit Clinton.

Trump has gained ground on Clinton in national opinion polls after revamping his campaign staff in August and taking steps to give a more polished performance on the campaign trail.

But he revived the birther controversy on Thursday in an interview with the Washington Post when he declined to say whether he believed Obama was born in Hawaii. A U.S. president must be a natural-born citizen.

The nonpartisan PolitiFact fact-checking website has rated the accusation that Clinton started the birther movement “false,” saying it appeared to begin with some Democrats who backed Clinton in 2008 but there were no ties to her or her campaign.

Trump had promised “a big announcement” about the birther issue, giving the impression it was the purpose of the event at his hotel.

But, instead, he held off saying anything about it through more than 20 minutes of endorsements from military veterans. Only after that did Trump make a brief statement about Obama’s birth.

Obama declined to comment on Trump’s revival of the birther issue, telling reporters he had better things to do.

“I’m shocked that a question like that would come up at a time when we’ve got so many other things to do – well, I’m not that shocked actually,” Obama said.

In 2011, Obama, the first African American to win the White House, released a long-form version of his birth certificate showing he was born in Hawaii.