Washington -US President Donald Trump posted a video Saturday from the hospital where he is battling Covid-19, saying he was improving and would be “back soon” -- but acknowledged that the crucial coming days would be “the real test.”

“I came here, wasn’t feeling so well. I feel much better now,” Trump said from his business suite at the Walter Reed military medical center near Washington. “We’re working hard to get me all the way back... I think I’ll be back soon and I look forward to finishing up the campaign the way it was started.”

Appearing relaxed in an open-collar shirt and blue suit jacket, Trump acknowledged that there was uncertainty about the course of the disease, which can hit recovering patients hard with no warning. “I’m starting to feel good. You don’t know over the next period of a few days, I guess that’s the real test, so we’ll be seeing what happens over those next couple of days.”

Late Saturday, White House doctor Sean Conley said Trump was “not yet out of the woods,” but that the medical team is “cautiously optimistic.”

White House Chief of Staff Mark Meadows said Trump’s condition had them worried on Friday but that he had since improved.

“Yesterday morning, we were real concerned... he had a fever and his blood oxygen level had dropped rapidly,” Meadows told Fox News late Saturday.

Meadows said there was never a risk trump would have to hand over power, after a day of conflicting reports and confusion over the leader’s actual fitness.

“He’s made unbelievable improvements from yesterday morning, when I know a number of us, the doctor and I, were very concerned,” Meadows said.

His comments echoed remarks by Conley, who said Trump had “made substantial progress since diagnosis, and remained “fever-free and off supplemental oxygen.”

Trump, 74, had completed a second dose of therapeutic drug remdesivir and had spent “most of the afternoon conducting business,” Conley added.