Washington, Donald Trump has tested negative for the novel coronavirus "on consecutive days", White House doctor Sean Conley said in the first public disclosure about the US President's health status after his October 2 announcement that he and the First Lady has contracted the disease.

Conley made the revelation in a memo on Monday shortly before Trump left for a re-election campaign rally in Sanford, Florida, his first since the announcement.

The physician said that Trump's latest Covid-19 results came from an antigen test from Abbott Laboratories, adding that a variety of laboratory data have all indicated that the virus was no longer active in the President's body, CNBC News reported.

"Repeatedly negative antigen tests, taken in context with additional clinical and laboratory data, including viral load, subgenomic RNA, and PCR cycle threshold measurements, as well as ongoing assessment of viral culture date, all indicate a lack of detectable viral replication," Conley wrote.

The memo, however memo did not specify on which consecutive days Trump had tested negative.

After the Florida rally, Trump will campaign in Pennsylvania on Tuesday and Iowa the following day.

Monday's development came after Trump made his first public appearance at a White House event on October 10.

At the South Lawn event, titled "Peaceful Protest in Support of Law and Order", the President addressed the attendants, many who did not wear masks or were socially distancing, from the Blue Room Balcony.

Trump wore a face mask but took it off later when he started addressing the gathering.

On October 8, Conley cleared the President for public engagements "based on the trajectory of advanced diagnostics the team has been conducting".