U.S. President Donald Trump said he hopes to resume campaigning Saturday after receiving a green light from his doctor, even as House Speaker Nancy Pelosi prepares to unveil plans to probe the president's capacity to govern after contracting COVID-19. 

Trump said in a Fox News interview late Thursday that he wants to hold a campaign rally as early as Saturday. "I think I'm going to try doing a rally on Saturday night if we have enough time to put it together," he said during an interview with Sean Hannity, adding that it would be "probably in Florida." 

Trump said that he might hold another rally the following day in Pennsylvania. 

Trump's physician Dr. Sean Conley said on Thursday that the president has completed his course of therapy for the coronavirus, and has remained stable since returning to the White House, and he could return to public engagements on Saturday.

Conley said in a memo released by the White House that Saturday will be 10 days since the president's diagnosis and Trump had responded "extremely well" to treatment.

Trump was hospitalised last Friday after he announced he had contracted the coronavirus. He returned to the White House on Monday.

"Since returning home, his physical exam has remained stable and devoid of any indications to suggest progression of illness," Conley wrote. 

"Saturday will be day 10 since Thursday's diagnosis, and based on the trajectory of advanced diagnostics the team has been conducting, I fully anticipate the President's safe return to public engagements at that time."

Trump, confined to the White House with the illness that he has sought to play down, said earlier on Thursday he did not believe he was contagious and was feeling good enough to resume campaign rallies. Such rallies, particularly held indoors, have raised concern among public health experts about spreading the virus. 

The president's positive test sidelined him from in-person events that have been the lifeblood of his campaign. Trump pulled out of a second debate with his rival Joe Biden after the Commission on Presidential Debates announced that the October 15 event would be held in a virtual format, with the candidates in separate locations, to ensure it could go forward whether or not Trump remained virus-free.

Meanwhile, House Speaker Nancy Pelosi unveiled plans Thursday to probe Trump's capacity to govern after he contracted COVID-19. With just 26 days until the November 3 election, Washington's top Democrat took the extraordinary step of proposing a commission to probe Trump's fitness for the job -- and whether he needs removal under the Constitution's 25th Amendment. 

Trump fired back on Twitter. "Crazy Nancy is the one who should be under observation," he wrote. "They don't call her Crazy for nothing!" 

(With input from agencies)