Donald Trump’s “vitals in the past 24 hours were very concerning”, according to sources familiar with the US President’s condition, even as Trump himself and his doctors sought to give a far more optimistic picture of his health while he underwent treatment for Covid-19 at a military hospital in Bethesda, Maryland.

In fact, according to multiple news media reports citing unidentified sources, the US president had been administered supplemental oxygen on Friday at the White House as his oxygen levels had dropped, which had reportedly prompted the decision to rush him to the Walter Reed Military Medical Center in Bethesda.

The gloomier updates came shortly after Sean Conley, the US president’s physician, and doctors at the military facility told reporters that Trump was “doing very well” and was in “exceptionally good spirits”.

Trump himself tweeted that he was “feeling well”.

First lady Melania Trump, who also tested positive for the coronavirus, was recuperating at the White House where she remained “well with only a mild cough and headache”.

An increasing number of aides and advisers who had been around the US president over the past few days have, in the meantime, continued to test positive one after another.

That included Kellyanne Conway, a former adviser to Trump, Bill Stepien, head of the Trump re-election campaign, and Chris Christie, the former New Jersey governor who helped Trump prepare for the first presidential debate against Democratic rival Joe Biden.

But conflicting updates on Trump’s health triggered both confusion and concern. “At this time, the team and I are extremely happy with the progress the president has made,” Conley said at Walter Reed, accompanied by the team of specialists and nurses looking after the American president. “Thursday, he had a mild cough and some nasal congestion and fatigue, all of which are now resolving and improving.”

Shaw Dooley, a lead specialist on the team, said the US president was “in exceptionally good spirits” and had said: “I feel like I could walk out of here today.”

A source familiar with the US president’s condition drew a slightly less optimistic picture of the situation. “The president’s vitals over the last 24 hours were very concerning and the next 48 hours will be critical in terms of his care,” the source told a White House pool of reporters in a background update, adding, “We’re still not on a clear path to a full recovery.”

Trump has been put on a five-day course of remdesivir at the hospital.

He has also been administered a single 8-gram dose of a cocktail of antibodies against the coronavirus, which is an experimental drug that hasn’t yet been approved for use. Apart from that, he was given zinc, Vitamin D, famotidine, melatonin and aspirin.

Trump was shifted to Walter Reed on Friday “out of an abundance of caution”, the White House had said earlier in the day.

There has been some confusion over the timeline of events. Conley had seemed to be suggesting that Trump had tested positive for Covid-19 72 hours ago, which was Wednesday, the day after the first presidential debate. But then he addressed an election rally in Duluth, Minnesota that day and then attended a fundraiser at his golf resort in New Jersey on Thursday.

The US president had announced on Friday morning that he and Melania had the virus. Later, Conley clarified that he had said 72 hours by mistake and the US president had tested positive on Thursday evening.

Though Trump is off the campaign trail, his campaign is not, signalling the urgency of the situation with Election Day just a month away. “Do you regret repeatedly attacking President Trump in a Michigan speech on the same day he was diagnosed with Covid-19?” the Trump campaign posted as the “question of the day” for Biden on Saturday.

But the campaign left out Biden’s concluding remarks: “I want to say god bless you, may god protect the first family and every family that is dealing with this virus, and may god protect our troops.”

The Biden campaign has also pulled down its negative ads on Trump.