US President Donald Trump said on Wednesday that John Bolton dismissed a day earlier as a national security adviser, had been a “disaster’ on North Korea policy.

Trump said that Bolton had made mistakes, including offending North Korea’s leader Kim Jong-un by demanding that he follow a “Libyan model” and hand over all his nuclear weapons.

“We were set back very badly when John Bolton talked about the Libyan model … what a disaster,” Trump said at the White House.

Trump said Bolton, with his abrasive, hardline approach, “wasn’t getting along with people in the administration that I consider very important.”

“John wasn’t in line with what we were doing,” he added.

Earlier on Wednesday, Trump asked John Bolton to resign as national security advisor.

Taking to Twitter, Trump wrote, “I thank John very much for his service. I will be naming a new National Security Advisor next week”.

The tweet came just one hour after the White House press office said Bolton was scheduled to appear at a press briefing alongside Secretary of State Mike Pompeo and Treasury Secretary Steve Mnuchin.

In response to Trump, Bolton also took to Twitter, saying “I offered to resign last night and President Trump said, ‘Let’s talk about it tomorrow.”

Trump had been growing more impatient with the failure to oust socialist Venezuelan President Nicolas Maduro through a US-led campaign of sanctions and diplomacy in which Bolton was a driving force.

North Korea has denounced Bolton as a “war maniac” and “human scum.” Last year, it threatened to call off the first summit between Kim and Trump after Bolton suggested the Libya model of unilateral disarmament. In the past, Bolton had proposed using military force to overthrow the country’s ruling dynasty.

Trump’s efforts to engage with North Korea nearly fell apart altogether in February after he followed Bolton’s advice at the second summit in Hanoi and handed Kim a piece of paper that called for the transfer of Pyongyang’s nuclear weapons and bomb fuel to the United States.