President Donald Trump said Tuesday he had fired National Security Adviser John Bolton after a string of disagreements between the two over how the U.S. should handle North Korea, Afghanistan and Iran.

Trump announced on Twitter that he had asked for Bolton's resignation, which he received this morning, after the president had "disagreed with many of his suggestions."

“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, and therefore I asked John for his resignation, which was given to me this morning,” Trump said on Twitter.