Trump saw physicians at Walter Reed military hospital on the outskirts of the capital Washington earlier in the day.

He gave reporters the thumbs-up on his return to the White House when they asked how the checkup had gone.

"President Trump continues to demonstrate excellent overall health," his doctor, Navy Captain Sean Barbabella, wrote in a letter released by the White House. 

"His cardiac age, a validated measure of cardiovascular vitality via ECG, was found to be approximately 14 years younger than his chronological age. He continues to maintain a demanding daily schedule without restriction."

A battery of routine tests was conducted, and Trump received an updated COVID-19 booster shot and his annual flu shot, Barbabella said.

The checkup comes three months after the White House announced that Trump had been diagnosed with a vein condition following speculation about frequent bruising on his hand and his swollen legs.

The White House had said earlier this week that Friday's checkup would be an "annual" one, despite the fact that Trump had already undergone one of those in April.

Trump told reporters in the Oval Office on Thursday that he was "going to do a sort of semi-annual physical."

"I'm in great shape, but I'll let you know. But no, I have no difficulty thus far [...] Physically, I feel very good. Mentally, I feel very good."

The Republican billionaire then embarked on one of his trademark tirades comparing his health with that of former presidents, particularly his Democratic predecessor Joe Biden.

Trump said that during his last checkup, "I also did a cognitive exam which is always very risky, because if I didn't do well, you'd be the first to be blaring it, and I had a perfect score."

Trump then added: "Did Obama do it? No. Did Bush do it? No. Did Biden do it? I definitely did. Biden wouldn't have gotten the first three questions right."

Trump has repeatedly been accused of a lack of transparency about his health despite huge interest in the well-being of the US commander-in-chief.

In September, he dismissed social media rumors swirling about his health, including false posts that he had died.

In July, the White House said Trump was diagnosed with a chronic but benign vein condition, chronic venous insufficiency, following speculation about his bruised hand and swollen legs. The hand issue, it said, was linked to the aspirin he takes as part of a "standard" cardiovascular health program.

Trump is regularly seen at public events with heavy makeup on the back of his right hand to conceal the bruising.

At his last checkup, the White House said Trump was in good health, saying he had a "normal cardiac structure and function, no signs of heart failure, renal impairment or systemic illness."