Is he being treated for Parkinson’s.

No, he’s not.

Is he taking medication for Parkinson’s.

No,” White House press secretary Karine Jean-Pierre told a briefing.

Biden is battling criticism from some Democrats that he lacks the mental acuity to stand as their nominee against Trump in the November 5 presidential election.

A Reuters review of White House visitor logs shows Dr Kevin Cannard, a neurologist and movement disorders specialist from Walter Reed National Military Medical Centre, visited the White House eight times from August to March.

Cannard has co-authored research on treatment for early Parkinson’s disease at Vanderbilt University Medical Centre.

Cannard met with White House physician Dr Kevin O’Connor at the White House in mid-January, the logs show.

Cannard’s visits to the White House were first reported by the New York Post on July 6.

A former White House official, who worked for Biden when he was Vice-President under President Barack Obama and as President, said they were treated by the same doctor for migraines in 2016.

The doctor came to the White House once a month then as part of his rotation, the ex-official said.

Jean-Pierre refused to confirm or elaborate on Cannard’s visits.

At the media briefing, she was frequently challenged by reporters and said she wanted to respect the privacy of all involved for security reasons.

She said Biden had seen a neurologist three times connected to his annual physical exam.

She did not explain Cannard’s presence at the White House, but suggested it might be connected to treating some of the military personnel who work at the White House complex.

“There are thousands of military personnel that come to the White House and they are under the care of the medical unit,” she said.