Update 2.56pm: Donald Trump has defended his decision to label President Barack Obama the "founder" of the so-called ‘Islamic State’ group.
Asked in an interview with CNBC whether it was appropriate for him to call the sitting president of the United States the founder of a terrorist organisation that wants to kill Americans, Mr Trump reaffirmed his accusation.
"He was the founder of Isis, absolutely," said Mr Trump - blaming the president for his decision to withdraw troops, which some argue created a power vacuum in which extremist groups like IS thrive.
Mr Trump said the US "should have never gotten in" the war, but also should not "have got out the way he got out".
Mr Trump now claims that he was opposed to the Iraq War from the beginning, despite evidence to the contrary.
Republican White House hopeful Donald Trump has accused US president Barack Obama of founding the Islamic State group that is wreaking havoc from the Middle East to European cities.
A moment later, on another topic, the billionaire property tycoon referred to the president by his full legal name, Barack Hussein Obama.
"In many respects, you know, they honour President Obama," Mr Trump said during a raucous campaign rally outside Fort Lauderdale, Florida. "He is the founder of Isis (another name for IS)."
He repeated the allegation three more times for emphasis.
In the past Mr Trump has accused his opponent, Democrat Hillary Clinton, of founding the militant group. As he shifted the blame to Mr Obama, he said "crooked Hillary Clinton" was actually the group's co-founder.
Mr Trump has long blamed Mr Obama and his former secretary of state Mrs Clinton for pursuing Middle East policies that created a power vacuum in Iraq that was exploited by IS.
He has sharply criticised Mr Obama for announcing he would pull US troops out of Iraq, a decision that many of the president's critics say created the kind of instability in which extremist groups like IS thrive.
The White House declined to comment on Mr Trump's accusation.
IS began as Iraq's local affiliate of al Qaida, the group that attacked the US on September 11 2001.
The group carried out massive attacks against Iraq's Shiite Muslim majority, fuelling tensions with al Qaida's central leadership. The local group's then-leader, Jordanian-born Abu Musab al-Zarqawi, was killed in 2006 in a US air strike, but is still seen as IS' founder.
Mr Trump's accusation, and his use of the president's middle name Hussein, echoed previous instances where he has questioned Mr Obama's loyalties.
In June, when a gunman who claimed allegiance to IS killed 49 people in an Orlando, Florida, nightclub, Mr Trump seemed to suggest Mr Obama was sympathetic to the group when he said the president "doesn't get it, or he gets it better than anybody understands".
In the past, Mr Trump has also falsely suggested Mr Obama is a Muslim or was born in Kenya, where Mr Obama's father was from.
The president, a Christian, was born in Hawaii.
Mr Trump lobbed the allegation midway through his rally at a sports arena, where excited supporters shouted obscenities about Mrs Clinton and joined in unison to shout "Lock her up!".
He railed against the fact that the Orlando shooter's father, Seddique Mateen, was spotted in the crowd behind Mrs Clinton during a rally in Florida on Monday, adding: "Of course he likes Hillary Clinton."
Sitting behind Mr Trump at the rally was former Florida congressman Mark Foley, who resigned in 2006 amid allegations that he sent sexually suggestive messages to former House of Representatives pages.