There are concerns the US president, who wore a mask, may have endangered Secret Service staff inside the car.

White House spokesperson Judd Deere said the trip on Sunday had been "cleared by the medical team as safe".

Questions remain over the seriousness of Mr Trump's illness after conflicting statements over the weekend.

President Donald Trump could be discharged from the hospital where he is being treated for COVID-19 as soon as Monday, according to his doctors, although his condition remains unclear and outside experts warn that his case may be severe.

The president has been in hospital since Friday, after he announced hours earlier he had tested positive for the virus.

Covid-19 has infected nearly 7.4 million and killed nearly 210,000 people across the US, according to Johns Hopkins University.