John Bolton, the Trump administration's hawkish national security adviser, is out of a job.

President Trump fired Bolton on Tuesday after the two failed to see eye-to-eye on the big foreign policy challenges facing the nation, including Iran, North Korea and Afghanistan.

Trump announced Bolton's firing on Twitter, noting he had "strongly disagreed with many of his suggestions."

"I informed John Bolton last night that his services are no longer needed at the White House," Trump wrote. "I disagreed strongly with many of his suggestions, as did others in the Administration, and therefore I asked John for his resignation, which was given to me this morning."

Trump said he would announce a new national security adviser next week. Bolton was the third person to hold the job since Trump took office in January 2017.