WASHINGTON — Republican presidential candidate Donald Trump on Friday acknowledged for the first time that President Obama was born in the United States, ending his long history of stoking unfounded doubts about the nation’s first African-American president but also seeking to falsely blame Democratic rival Hillary Clinton for starting the rumors.

“Hillary Clinton and her campaign of 2008 started the birther controversy. I finished it. I finished it, you know what I mean,” Trump said at his newly opened luxury hotel in Washington on Friday morning. “President Barack Obama was born in the United States. Period.”

This is not the first time that Trump has accused Clinton of first raising questions about Obama’s birthplace, an assertion that has been repeatedly disproven by fact-checkers who found no evidence that Clinton or her campaign questioned Obama’s birth certificate or his citizenship.

“For five years, he has led the birther movement to delegitimize our first black president,” Clinton said on Friday, demanding that Trump apologize to Obama. “His campaign was founded on this outrageous lie. There is no erasing it in history.”

For years, Trump has been the most prominent backer of the so-called birther movement, which lurked in the dark corners of the Internet until Trump forced it into the mainstream. While drumming up publicity for his own possible run for the White House during the last election cycle, Trump began to aggressively question Obama’s qualifications for office. Trump never came out and said where he thinks the president was born, but he demanded to see the president’s long-form birth certificate and other records. Trump also claimed to have hired investigators.

In April 2011, Obama released his long-form Hawaiian birth certificate in the name of putting all of the conspiracy theories to rest, and Trump congratulated himself and said that he “accomplished something that nobody else has been able to accomplish.”

But Trump didn’t revise his position and repeatedly questioned the validity of the document Obama released. In an October 2011 interview with CNN, Trump said that if “you check out the internet, many people say it is not real.” In August 2012, Trump tweeted that “an ‘extremely credible source’ has called my office and told me that @BarackObama’s birth certificate is a fraud.”

Obama and his allies have repeatedly said they have never had any doubt about where the president was born.

“I was pretty confident about where I was born,” Obama told reporters in the Oval Office on Friday. “I think most people were as well.”

Days before the 2012 election, Trump posted a video online that labeled Obama “the least transparent president in the history of this country” and demanded that Obama release his college records, college applications and passport records.  Trump said that if he ran for president, he would release his tax returns — something that he now refuses to do because he says several years of his returns are under audit by the Internal Revenue Service. Trump is the first nominee from a major party since 1976 to not release his returns, and he has also declined to release documentation of his wife’s immigration from Slovenia, full medical records and other documents typically shared by nominees.

When Trump launched his long-shot presidential bid in June 2015, he continued to say in interviews that he didn’t know if Obama was born in the United States, but he didn’t dwell on the issue as he once did. On the campaign trail, Trump repeatedly suggested that the president might not be Christian or that he might sympathize with Islamic State terrorists. In January, Trump said on CNN that he doesn’t know where the president was born.

“Who knows? Who knows? Who cares right now,” Trump said on Jan. 6 on CNN. “We’re talking about something else, okay? I mean, I have my own theory on Obama. Someday I’ll write a book. I’ll do another book, and it will do very successfully.”

A sizable number of voters agreed with Trump. A 2010 Washington Post-ABC News poll found 20 percent saying Obama was born in another country while 77 percent said he was born in the United States. Misperceptions plummeted to 10 percent in a 2011 Post-ABC poll after Obama released his long-form birth certificate, but a CNN-ORC poll last September found they had again returned to 20 percent.

In the latest survey, beliefs that Obama was born outside the United States peaked at 26 percent among Republicans and 34 percent among self-identified tea party supporters, compared with 19 percent of independents and 12 percent of Democrats. Among all those who said Obama was born outside the United States, about half thought there is “solid evidence” for their view while the rest said this was only their suspicion.

Such attacks have caused many black voters to turn sharply against Trump, offended that he would challenge the qualifications of the country’s first black president. As Trump began to make an aggressive pitch to minority voters in August, there was renewed debate over Trump’s prominent role in the birther moment. On Labor Day, reporters aboard Trump’s plane asked him where the president was born, and Trump refused to answer.

“I don’t talk about it because if I talk about that, your whole thing will be about that,” Trump said. “So I don’t talk about it.”

Earlier this month, former Republican candidate Ben Carson — who now advises Trump on race issues — said on CNN that Trump could immediately improve his relationship with African-American voters by apologizing for questioning the president’s place of birth. Trump’s top campaign aides insisted that the Republican nominee believes that Obama was born in Hawaii.

In an interview with The Washington Post that was published on Thursday, Trump was unwilling to say that President Obama was born in the United States.

“I’ll answer that question at the right time,” Trump said in an interview in Ohio on Wednesday night. “I just don’t want to answer it yet.”

“You watch my statement,” Trump said. “We have to keep the suspense going. Okay? So you watch.”

Scott Clement, Anne Gearan and David Nakamura contributed to this report.