Trump later said that the US had the 'greatest economy ever' before the COVID-19 outbreak hit the country further. He also termed the virus "as an artificial horrible situation".
Trump, who trails in the polls ahead of the November 3 election, was especially under pressure about the coronavirus that has killed over 217,000 Americans and inflicted deep economic damage.
"This comprehensive data, in concert with the CDC's guidelines for removal of transmission-based precautions, have informed our medical team's assessment that the President is not infectious to others."
As Trump prepared to leave the White House for the first time since returning on October 5 after three nights at Walter Reed Medical Center, he fired off a series of tweets.
The Democratic presidential candidate's campaign does not allow a large gathering because of COVID-19 restrictions, with at the most a score of people sitting at a distance.
Polls show Biden leads heavily in key demographics including women and the elderly, prompting analysts to talk increasingly of a possible landslide victory.