Donald Trump has claimed Barack Obama and Hillary Clinton are to blame for the creation of Isis.
During his latest campaign rally in Mississippi, Mr Trump suggested the Obama administration has allowed the extremist group to flourish by ignoring his call for the US to seize oil assets now owned by Isis.
“I’ve predicted a lot of things, you have to say, including, ‘Get the oil, take the oil, keep the oil’. Right?” he said.
“I’ve been saying that for three years, and everybody said, ‘Oh I can’t do that. I mean, this is a sovereign country.’ There is no country!
“They’ve created Isis. Hillary Clinton created Isis with Obama,” he continued.
Mr Trump gave no evidence to support his claims, but used his address to accuse Iran of wanting to take over Saudi Arabia, a long-time US ally.
This comes during Iranian protests outside the Saudi embassy in Tehran, which erupted after the mass executions of 47 Sunni and Shia prisoners by Saudi Arabia.
Donald Trump's most controversial quotes
Donald Trump's most controversial quotes
1/14 On Isis:
"Some of the candidates, they went in and didn’t know the air conditioner didn’t work and sweated like dogs, and they didn’t know the room was too big because they didn’t have anybody there. How are they going to beat ISIS?"
2/14 On immigration:
"I will build a great wall — and nobody builds walls better than me, believe me —and I’ll build them very inexpensively. I will build a great, great wall on our southern border, and I will make Mexico pay for that wall. Mark my words."
3/14 On Free Trade:
"Free trade is terrible. Free trade can be wonderful if you have smart people. But we have stupid people."
PAUL J. RICHARDS | AFP | Getty Images
4/14 On Mexicans:
"When Mexico sends its people, they’re not sending their best. They’re sending people that have lots of problems. They’re bringing drugs. They’re bringing crime. They’re rapists."
5/14 On China:
"I just sold an apartment for $15 million to somebody from China. Am I supposed to dislike them?... I love China. The biggest bank in the world is from China. You know where their United States headquarters is located? In this building, in Trump Tower."
6/14 On work:
"If you're interested in 'balancing' work and pleasure, stop trying to balance them. Instead make your work more pleasurable."
7/14 On success:
"What separates the winners from the losers is how a person reacts to each new twist of fate."
8/14 On life:
"Everything in life is luck."
9/14 On ambition:
"You have to think anyway, so why not think big?"
10/14 On his opponents:
"Bush is totally in favour of Common Core. I don't see how he can possibly get the nomination. He's weak on immigration. He's in favour of Common Core. How the hell can you vote for this guy? You just can't do it."
11/14 On Obamacare:
"You have to be hit by a tractor, literally, a tractor, to use it, because the deductibles are so high. It's virtually useless. And remember the $5 billion web site?... I have so many web sites, I have them all over the place. I hire people, they do a web site. It costs me $3."
12/14 On Barack Obama:
"Obama is going to be out playing golf. He might be on one of my courses. I would invite him. I have the best courses in the world. I have one right next to the White House."
13/14 On himself:
"Love him or hate him, Trump is a man who is certain about what he wants and sets out to get it, no holds barred. Women find his power almost as much of a turn-on as his money."
14/14 On America:
"The American Dream is dead. But if I get elected president I will bring it back bigger and better and stronger than ever before and we will make America great again."
“In Tehran, they’re burning down the Saudi embassy, you see that?” he said. “Now, what this is is Iran wants to take over Saudi Arabia. They always have. They want the oil, ok? They’ve always wanted that.”
After the rally, he retweeted a supporter who repeated his claims about Ms Clinton and Mr Obama. The supporter was responding to a critic calling Mr Trump a "retard" and a "douche".
In November 2015, Mr Trump’s fellow Republican candidates Rick Santorum and Carly Fiorina both said that Ms Clinton and Mr Obama were to blame for the rise of Isis.
Mr Trump made no comment on the al-Shabaab recruitment video that was released on Friday, featuring footage of him calling for a ban on all Muslims entering the US.