WASHINGTON, Sept. 10 (CGTN) -- U.S. 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 the Democratic People's Republic of Korea (DPRK), 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," Trump tweeted on Tuesday, adding that he would name a replacement next week.

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

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

The announcement followed an acrimonious conversation on Monday that included their differences over Afghanistan, said a source familiar with the matter.

The 70-year-old Bolton, who took up the post in April 2018, replacing H.R. McMaster, had also often been at odds with Secretary of State Mike Pompeo, a Trump loyalist.

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

Possible successors?

Stephen Biegun, special U.S. envoy on the DPRK, is among the names that have been floated as possible successors.

"Biegun is 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 U.S. ambassador to Russia, and Richard Grenell, U.S. ambassador to Germany, people familiar with the matter said.

White House spokeswoman Stephanie Grisham said "many, many issues" led to Trump's decision to ask for Bolton's resignation. She would not elaborate.