US President Donald Trump has announced he has sacked White House National Security Adviser John Bolton, saying he is no longer needed in the White House.

"I informed John Bolton last night that his services are no longer needed at the White House," Trump wrote in a twit.

"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. I thank John very much for his service."

Trump added that he will be naming a new National Security Advisor next week. (ILKHA)