In a memo released by the White House, Dr Sean Conley said Mr Trump had been tested using an Abbott Laboratories BinaxNOW antigen card.
He said the negative tests and other clinical and laboratory data "indicate a lack of detectable viral replication".
The US president announced he had tested positive for coronavirus on 2 October.
He was admitted to Walter Reed military hospital that night and released three days later.
Mr Trump, who is trailing behind his Democratic rival Joe Biden in the polls ahead of next month's presidential election, is holding an election rally in Florida on Monday.
The president is beginning a three-day tour of states he needs to win to defeat Mr Biden in three weeks' time.
Mr Trump will appear in Pennsylvania on Tuesday and Iowa on Wednesday.
He had earlier claimed he had a "protective glow" after being given the all-clear from coronavirus by White House medical staff.
Mr Trump also declared himself immune to the virus, despite official guidance from the US Centres for Disease Control and Prevention warning that recovering from COVID-19 does not make a patient immune.
A leading US virus expert criticised the White House over the weekend for hosting a ceremony in September that turned out to be a "superspreader event".
Dr Anthony Fauci, an infectious diseases expert and member of the White House's coronavirus task force, also criticised Mr Trump's use of the word "cure" when discussing his recovery from the illness.
A number of the president's aides and allies tested positive for COVID-19 after attending a Rose Garden event where the Mr Trump unveiled Amy Coney Barrett as his Supreme Court pick.
The threat of coronavirus hung over the opening confirmation hearing for Ms Barrett on Monday - after at least one senator present had tested positive for the disease.