Within minutes of Donald Trump's arrival at the Walter Reed Medical Centre in Bethesda, Maryland, groups of his supporters started to gather at the entrance to the hospital.

They maintained a presence all weekend, carrying banners and flags. They waved and cheered as passing cars beeped their horns.

A woman carried a sign that read: "Prognosis: four more years in the White House".

Other placards simply read: "Get Well Soon".

Similar tributes and cards had been left alongside bunches of flowers at the hospital gates.

At one point today, a group of supporters bowed their heads as a man on a loudspeaker prayed for the US president's health.

Ken Deibler was holding a large poster depicting Donald Trump as the action hero Rambo.

"I have faith that he is a strong warrior and that he will defeat the virus and make short order of it," he said.

A woman who was carrying an American flag said she rejected criticism that Donald Trump had not been taking the virus seriously.

"We don't know when that bug entered him. He could have had a mask on and maybe he touched a surface and touched his eye. It is unfortunate but he is human just like us," she said.

A man wearing a Donald Trump hat and face mask said he was confident the US president would be fine.

"He's going to recover and frankly, to be a little tongue-in-cheek, I thought he needed the break," he said.