President Donald Trump said former National Security Advisor John Bolton, who resigned on Tuesday, made some “big mistakes” during his time at the White House which is why he was asked to leave.

The president spoke to reporters on Wednesday, citing his differences with Bolton on how to handle North Korea and Venezuela and Bolton’s support for the war in Iraq.

Trump said that Bolton delivered a setback to his efforts for peace with North Korea.

“He made some very big mistakes when he talked about the Libyan model for Kim Jong Un,” Trump said. “That was not a good statement to make.”

Trump added that although Bolton was a “tough guy,” he made mistakes, noting that he was a supporter of the United States invasion of Iraq in the Bush administration.

“That’s not a question of being tough, that’s a question of being not smart saying something like that,” he said.

He also referred to Bolton’s views on Venezuela but did not detail his differences with his former national security advisor.

“I disagreed with John Bolton on his attitudes on Venezuela. I thought he was way out of line and I think I’ve proven to be right,” he said.

Trump also criticized Bolton for failing to get along with other members of his administration.

“He’s somebody that I actually had a very good relationship with, but he wasn’t getting along with people in the administration who I consider very important,” he said.

Trump acknowledged that Bolton would try to “spin” the story to suggest that he resigned first, but asserted that he had asked for his resignation.

“I hope we’ve left in good standing, maybe we have and maybe we haven’t,” he said. “I have to run the country the way we’re running the country.”

He confirmed that there were about five different people he was considering to take Bolton’s former position and would announce a replacement soon.