Trump replaces national security adviser HR McMaster with former UN ambassador John Bolton in latest White House shake-up

Donald Trump is replacing national security adviser HR McMaster with the hawkish former Ambassador to the United Nations John Bolton in the latest administration shake-up.

In a sign of the administration's unusually high rate of turnover, the pro-Iraq war hardliner will become Mr. Trump's third National Security Adviser.

"General McMaster's leadership of the National Security Council staff has helped my administration accomplish great things to bolster America's national security. He helped develop our America First National Security Strategy, revitalize our alliances in the Middle East, smash ISIS, bring North Korea to the table, and strengthen our nation's prosperity," Mr. Trump said in a statement.

The President said on Twitter that an official handover would occur in April.

"I am thankful to President Donald J. Trump for the opportunity to serve him and our nation as national security advisor. I am grateful for the friendship and support of the members of the National Security Council who worked together to provide the President with the best options to protect and advance our national interests," Mr. McMaster said in a statement.

Mr. Trump's initial pick for the role, General Michael Flynn, stepped aside after it emerged he had misled officials about conversations with the then-Russian ambassador; Mr. Flynn subsequently pleaded guilty to lying to FBI agents who were investigating potential coordination between the Russian government and the Trump presidential campaign.

In elevating Mr. Bolton, a staunch proponent of the Iraq war, the President has chosen an aide whose support for military entanglements abroad would seem to clash with Mr. Trump's "America First" instincts and campaign promises to emphasise domestic issues.

The change also comes at a key moment for the Trump administration's foreign policy after the President committed to what would be an unprecedented meeting with North Korean leader Kim Jong-un to discuss denuclearisation.

In an interview with Fox News, Mr. Bolton called the appointment "a great honour."

"I've never been shy about what my views are, but frankly what I have said...is behind me, at least effective 9 April," Mr. Bolton said. "The important thing is what the President says and what advice I would give him."

A hawkish figure who rose to prominence under George W Bush and a vocal supporter of the American invasion of Iraq, Mr. Bolton served in the State Department during Mr. Bush's first term before becoming America's ambassador to the United Nations.

Critics called the ambassador post an inappropriate choice given Mr. Bolton's history of assailing the international body, and Democrats later helped force his resignation by blocking a confirmation vote.

Mr. Bolton has also been a fierce critic of Iran and North Korea, two countries that Mr. Trump has forcefully criticised and that will likely continue to feature prominently in the Trump administration's global posture.

In 2003, when he was serving as America's chief arms control diplomat, Mr. Bolton delivered a speech in Seoul, South Korea, denouncing then-North Korean leader Kim Jong Il as "a tyrannical dictator" whose country resembled a "hellish nightmare."

The President is no stranger to using vivid language to denounce North Korea, threatening the regime of Kim Jong-un with military force as the country menaced neighbours and tested multiple intercontinental ballistic missiles in recent months.

But Mr. Trump has also embraced a diplomatic opening with his extraordinary agreement to meet with Mr. Kim. His openness to negotiating an end to North Korea's nuclear programme contrasts with Mr. Bolton's repeated recent declarations that diplomatic approaches to North Korea cannot succeed.

In late February, shortly before the White House announced Mr. Trump had accepted Mr. Kim's offer to meet, Mr. Bolton wrote an op-ed backing a preemptive military strike on North Korea.

Mr. Bolton also shares Mr. Trump's suspicion of Iran, a country the President has singled out as a threat to the United States.

Mr. Trump has frequently excoriated a deal forged during the Obama administration to halt Iran's nuclear programme.

Warning Mr. Obama's approach towards Iran "has brought a bad situation to the brink of catastrophe," Mr. Bolton in 2015 authored an op-ed advocating a military strike on Iran's nuclear facilities.

"The inescapable conclusion is that Iran will not negotiate away its nuclear program. Nor will sanctions block its building a broad and deep weapons infrastructure," Mr. Bolton wrote, saying that "only military action" can "accomplish what is required."

That background prompted an outcry from Democrats in response to Mr. Trump's selection of Mr. Bolton. Rep Brendan Boyle of Pennsylvania called him a "dangerous radical" with a record of "undermining key alliances around the world," and several lawmakers said he had been discredited by his support for the Iraq war.

"Bolton played a key role in politicizing the intel that misled us into the Iraq War. We cannot let this extreme war hawk blunder us into another terrible conflict," Senator Edward Markey, a Massachusetts Democrat, said on Twitter.