Joe Biden's doctor insists he has shown no signs of Parkinson's disease

Joe Biden faces continued pressure to stand down as the Democratic Presidential candidate, as ITV News US Correspondent Dan Rivers reports from Washington

Joe Biden's doctor says the US president has shown no signs of Parkinson's disease, after reports emerged that a specialist visited the White House several times in the past year.

Dr Kevin O'Connor, the White House physician, released a letter on Monday night that revealed Biden "has not seen a neurologist outside of his annual physical".

The letter also showed that the 81-year-old president had been tested for a number of neurological diseases, including Parkinson's, with no positive results returned.

In recent weeks, Biden has faced calls from some Democrats to withdraw from November's US presidential election, owing to his head-to-head debate performance against Donald Trump.

But in a letter to congressional democrats earlier on Monday, Biden dismissed calls for him to drop out.

White House visitor logs, carried by the New York Times, showed that a Parkinson's specialist - Dr Kevin Cannard - visited the White House eight times over the past year, although the exact nature of the meetings is unknown.

Dr Cannard is shown to have met with Dr O'Connor and another White House staff member on January 17.

Dr O'Connor wrote in his letter that Dr Cannard "has held regular Neurology Clinics at the White House Medical Clinic in support of the thousands of active-duty members assigned in support of White House operations".

He added: "Many military personnel experience neurological issues related to their service, and Dr Cannard regularly visits the WHMU as part of this General Neurology practice."

In response to questions about the nature of the January 17 meeting, a White House spokesperson said: "A wide variety of specialists from the Walter Reed system visit the White House complex to treat the thousands of military personnel who work on the grounds."

White House press secretary Karine Jean-Pierre later told reporters that Biden had been seen by a neurologist three times during his presidency - once during each of his annual physicals.

But she declined to name the neurologists or explain why Dr Cannard had visited the White House eight times over the past year.

In 2016, then-president Trump created headlines after releasing his own doctor's letter, which detailed him as being in "excellent physical health".

The letter, signed by Trump's personal physician Dr Harold Bornstein, said that, at the time, he had been hospitalised only once - when his appendix was taken out aged 11.

Want a quick and expert briefing on the biggest news stories? Listen to our latest podcasts to find out What You Need To Know…