WASHINGTON (REUTERS) - United States President Donald Trump abruptly fired his national security adviser John Bolton amid disagreements with his hard-line aide over how to handle foreign policy challenges such as North Korea, Iran, Afghanistan and Russia.

"I informed John Bolton last night that his services are no longer needed at the White House. I disagreed strongly with many of his suggestions, as did others in the Administration," Mr Trump tweeted on Tuesday (Sept 10), adding that he would name a replacement next week.

Mr Bolton, a leading foreign policy hawk and Mr Trump's third national security adviser, had pressed the President not to let up pressure on North Korea despite diplomatic efforts.

Mr Bolton, a chief architect of Mr Trump's strident stance against Iran, had also argued against the President's suggestions of a possible meeting with the Iranian leadership and advocated a tougher approach on Russia and, more recently, Afghanistan.

Mr Trump's announcement of Mr Bolton's departure followed an acrimonious conversation on Monday night that included their differences over Afghanistan, said a source familiar with the matter.

Mr Bolton, 70, who took up the post in April 2018, replacing former general H. R. McMaster, had also often been at odds with Secretary of State Mike Pompeo, one of Mr Trump's main loyalists.

Mr Pompeo acknowledged he and Mr Bolton often had differences but he told reporters: "I don't think that any leader around the world should make any assumption that because some one of us departs that President Trump's foreign policy will change in a material way."

Offering a different version of events than Mr Trump, Mr Bolton tweeted: "I offered to resign last night and President Trump said, 'Let's talk about it tomorrow.'"

Mr Trump had sometimes joked about Mr Bolton's image as a warmonger, reportedly saying in one Oval Office meeting that "John has never seen a war he doesn't like".

A source familiar with Mr Trump's view said Mr Bolton, an inveterate bureaucratic infighter with an abrasive personality, had ruffled a lot of feathers with other key players in the White House, particularly chief of staff Mick Mulvaney.

"He (Bolton) doesn't play by the rules," the source said. "He's a kind of a rogue operator."

During his time at the State Department under the administration of Republican former president George W. Bush, Mr Bolton kept a defused hand grenade on his desk. His 2007 memoir is entitled: Surrender Is Not An Option.

Mr Trump's North Korea envoy, Mr Stephen Biegun, is among the names that have been floated as possible successors.

"Biegun, much more like Pompeo, understands that the president is the president, that he makes the decisions," said a source close to the White House.

Also considered in the running is Deputy Secretary of State John Sullivan, who had been expected to be named US ambassador to Russia, and Mr Richard Grenell, US ambassador to Germany, people familiar with the matter said.

White House spokesman Stephanie Grisham said "many, many issues" led to Mr Trump's decision to ask for Mr Bolton's resignation.

She would not elaborate.

'HE'LL BOMB YOU'

Mr Trump would sometimes chide Mr Bolton about his hawkish ways in meetings, introducing him to visiting foreign leaders by saying: "You all know the great John Bolton. He'll bomb you. He'll take out your whole country."

Officials and a source close to Mr Trump said the President had grown weary of his hawkish tendencies and bureaucratic battles.

Mr Bolton, a former US ambassador to the United Nations and Fox News television commentator, had opposed a recent State Department plan to sign an Afghan peace deal with the Taleban militia, believing the group's leaders could not be trusted.

Among the points of contention was Mr Trump's intention - called off by the President at the last minute - to bring Taleban leaders to the Camp David presidential retreat last weekend to finalise an accord just days before the 18th anniversary of the Sept 11, 2001 attacks.

Sources familiar with his view said Mr Bolton believed the US could draw down to 8,600 troops in Afghanistan and maintain a counter-terrorism effort without signing a peace deal with the Taleban.

US officials have said it was Mr Bolton who was responsible for the collapse of a summit in February between Mr Trump and North Korean leader Kim Jong Un in Hanoi by recommending a list of hard-line demands that Mr Kim rejected.

North Korea media in May referred to Mr Bolton as a "war maniac" who "fabricated various provocative policies such as designation of our country as 'axis of evil', preemptive strike and regime change".

Mr Bolton's departure - the latest in a series from Mr Trump's national security team in recent months - comes a day after North Korea signalled a new willingness to resume stalled denuclearisation talks with the US, but then continued with a recent spate of missile launches.

US oil prices fell more than 1 per cent on the news of Mr Bolton's departure, with investors believing it could lead to a softer US policy on Iran.

Mr Bolton had spearheaded Mr Trump's policy against Iran, including the US abandonment of an international nuclear deal with Teheran and reimposition of US sanctions.

Mr Bolton was widely believed to have favoured a planned US air strike on Iran earlier this year in retaliation for the downing of a US surveillance drone, an action Mr Trump called off at the last minute. Mr Trump has since expressed a willingness to talk to Iranian leaders under the right conditions, something Mr Bolton is known to have opposed.

An adviser to Iranian President Hassan Rouhani said Mr Trump's firing of Mr Bolton pointed to the failure of Washington's "maximum pressure strategy in the face of the constructive resistance of Iran".

Mr Bolton, a long-time harsh critic of Russian President Vladimir Putin, was also against Mr Trump's insistence that Moscow be allowed to rejoin the Group of Seven world powers despite its continued occupation of Ukraine's Crimea.

Mr Bolton was an ardent opponent of arms control treaties with Russia. He was instrumental in Mr Trump's decision to withdraw last month from a 1987 accord that banned intermediate-range missiles because of what Washington charged was Moscow's deployment of prohibited nuclear-capable cruise missiles, an allegation Russia denied.

Mr Bolton, an unabashed advocate of US power, has sharply criticised international institutions like the United Nations.

Last year, he said the US would ban and prosecute officials of the "unaccountable" International Criminal Court if the court moved to bring war crimes charges against any American who served in Afghanistan or launched cases against Israel or other US allies.

While Mr Trump and Mr Bolton appeared mostly in sync about efforts to push Venezuelan President Nicolas Maduro from power, Mr Trump had grown increasingly impatient about the failure of a US campaign of sanctions and diplomacy to unseat the socialist leader.