Medical experts are questioning Donald Trump’s decision to greet supporters in a drive-past outside the hospital where he is being treated for Covid-19.

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.

Speaking on Fox News, White House chief of staff Mark Meadows said doctors would decide later whether the president could be discharged from Walter Reed hospital, near Washington, on Monday.

Mr Meadows said he had spoken with Mr Trump earlier, and that his condition appeared to have improved overnight.

The president was taken to hospital on Friday evening, hours after announcing he had tested positive for the virus.

President Trump’s diagnosis has upended his election campaign, as he faces Democratic challenger Joe Biden on 3 November.

A growing number of people around the president, including his wife Melania Trump, senior aides and Republican senators, have tested positive with the virus.

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