WASHINGTON - Chairman of White House Council of Economic Advisers Kevin Hassett will step down "shortly," US President Donald Trump tweeted Sunday.

"Kevin Hassett, who has done such a great job for me and the Administration, will be leaving shortly," Trump said, adding that he will name Hassett's successor as soon as he returns from a trip to Europe.

The president in the tweet also thanked Hassett "for all he has done" and said he is a "true friend."

Trump didn't say whether Hassett resigned or was fired, nor did he elaborate on the reason for the personnel change.

Hassett, a 57-year-old Republican from Massachusetts, was sworn in on Sept. 13, 2017 as the 29th chairman of the Council of Economic Advisers.

Starting Monday, Trump will embark on a week-long European trip to visit Britain, Ireland and France.