President Donald Trump is in "excellent health," and has no cognitive problems, but should lose some weight through a regimen that includes improving his diet and getting more exercise, the White House physician said Tuesday.

"Absolutely, he's fit for duty, I think he will remain fit for duty for the remainder of his term," said Dr. Ronny Jackson, who oversaw Trump's first annual physical exam as president last Friday.

"The president's overall health is excellent."

"There's no indication whatsoever that he has any cognitive issues," Jackson told reporters at a White House news briefing.

"I find no reason whatsoever to think that the president has any issues whatever with his thought process."

The White House later released a three-page summary of the exam.

Trump himself asked for an evaluation of his cognitive state, after questions were recently raised about it by a new book about the president, "Fire and Fury," said Jackson, who is a rear admiral in the U.S. Navy.

"He asked me to do it," Jackson said of Trump, 71, who last year became the oldest person ever to become president.