President Donald Trump spent more than two hours at Walter Reed National Medical Center on Saturday for medical tests, which Mr Trump says were "great".

The appointment wasn't on Trump's weekend public schedule, and his last physical was in February. Press secretary Stephanie Grisham said the 73-year-old president was "anticipating a very busy 2020" and wanted to take advantage of "a free weekend" in Washington to begin portions of his routine checkup.

She did not specify which tests he'd received or explain why the visit had not been disclosed in advance. Mr Trump's 2018 and 2019 physicals were both announced ahead of time and appeared on his public schedule.

Mr Trump tweeted: "Visited a great family of a young man under major surgery at the amazing Walter Reed Medical Center. Those are truly some of the best doctors anywhere in the world. Also began phase one of my yearly physical. Everything very good (great!). Will complete next year."

Ms Grisham said after the visit that the president had had "a quick exam and labs".

"The President remains healthy and energetic without complaints, as demonstrated by his repeated vigorous rally performances in front of thousands of Americans several times a week," she said.