The medical team treating US President Donald Trump are “cautiously optimistic” but say he is “not yet out of the woods”.

The latest assessment came on Saturday night from Dr Sean Conley, who reported Mr Trump had been up and around at his medical suite during the day and had been conducting business.

Mr Trump was taken to the Walter Reed Medical Centre on Friday, with a White House spokeswoman saying he was expected to stay for “a few days”.

In a video from his hospital quarters posted on Saturday, Mr Trump says he is feeling better and hopes to “be back soon”.

He defended his decision to continue campaigning and holding large events in the midst of a pandemic.

“I had no choice,” said Mr Trump, who refused to abide by basic public health recommendations, including mask-wearing.

“I had to be out front … I can’t be locked up in a room upstairs and totally safe. As a leader, you have to confront problems.”

Mr Trump also thanked his medical team and hailed the state-of-the-art treatments he was receiving, comparing them to “miracles coming down from God.”

The bright assessment of Mr Trump’s condition from White House doctors was in contrast to that given by his chief of staff Mark Meadows. In a briefing to reporters soon after Dr Conley gave his assessment, Mr Meadows said the president went through a “very concerning” period on Friday and faced a “critical” next two days in his fight against Covid-19.

Mr Trump is 74 years old and clinically obese, putting him at higher risk of serious complications from a virus that has infected more than seven million people and killed more than 200,000 in the US.

The administration has consistently been less than transparent about the president’s health as the virus spread inside the White House.

Aides declined to share basic health information about the president, including a full accounting of his symptoms, what tests he has undertaken and the results.

Also, the first word that a close aide to Mr Trump had been infected came from the media, not the White House.

In a memo released late on Friday, Dr Conley did report Mr Trump had been treated at the hospital with remdesivir, an antiviral medication, after taking another experimental drug at the White House.

Meanwhile, the White House has been working to trace a flurry of new infections of close Trump aides and allies.

Attention is focused in particular on last Saturday’s White House event introducing Mr Trump’s Supreme Court nominee.

That day, Mr Trump gathered more than 150 people in the Rose Garden, where they mingled, hugged and shook hands.

There were also several indoor receptions, where Mr Trump’s Supreme Court pick, Judge Amy Coney Barrett, her family, senators and others spent time in the close quarters of the White House, photographs show.

Among those who attended and have now tested positive include former New Jersey Governor Chris Christie, White House counsellor Kellyanne Conway, the president of the University of Notre Dame, and at least two Republican senators, Mike Lee and Thom Tillis.

The president’s campaign manager, Bill Stepien, and the head of the Republican National Committee, Ronna McDaniel, have also tested positive, though they were not at the event.

Despite its failure to protect the president and senior staff from infection, the White House has given no indication that it intends to make any major protocol changes, such as mandating that everyone wears a mask.