Donald Trump’s doctor Harold Bornstein has said he spent just 5 minutes on a letter endorsing the Republican candidate’s health, while Trump’s car waited outside.

Dr. Harold Bornstein told NBC News: “In the rush I think some of those words didn’t come out exactly the way they were meant.”

The doctor’s letter said Donald Trump, 70, would be the “healthiest individual ever elected to the presidency”.

Harold Bornstein, of York’s Lenox Hill Hospital, said he “picked up” the candidate’s own “kind of language” when writing it.

Two weeks before the note was written, Donald Trump tweeted to say he had “instructed my long-time doctor to issue, within two weeks, a full medical report”, adding that it would “show perfection”.

Donald Trump later highlighted the endorsement from Dr. Harold Bornstein, who faced questions about its exaggerated tone.

Dr. Harold Bornstein says he may have overstated the case “so that they [the Trump campaign] would be happy”.

“I think I picked up his kind of language and then I just interpreted it to my own,” he said.

Donald Trump would be the oldest person to be elected US president, were he to win in November. His rival Democratic candidate Hillary Clinton is 68-year-old.

The health of two candidates has become a focal point in the campaign, with Donald Trump repeatedly alleging that Hillary Clinton is physically unfit.

Hillary Clinton has hit back at what she says are unfounded allegations, and Donald Trump has faced criticism over the personal nature of the attacks.

Neither candidate has divulged their full medical record. Hillary Clinton released a statement from her doctor, Lisa Bardack, in 2015.

Dr. Lisa Bardack said: “She is excellent physical condition and fit to serve as President of the United States.”