Washington, Dec 21 (IANS) US President Donald Trump has said Defence Secretary Jim Mattis is to retire at the end of February.

Mattis will "be retiring, with distinction", after having served the administration as the defence chief for the past two years, Trump tweeted on Thursday, Xinhua news agency reported.

"During Jim's tenure, tremendous progress has been made, especially with respect to the purchase of new fighting equipment," the President said.

He added that a new secretary of defence "will be named shortly".

--IANS pgh/