Dominic Raab has not spoken to Boris Johnson since taking over his responsibilities, insisting the Prime Minister should focus on his recovery.
The Foreign Secretary, who is deputising for the PM, added he has “got all the authority I need” to take decisions along with his Cabinet colleagues.
Downing Street said on Thursday evening Mr Johnson had been moved from intensive care, where he spent three nights being treated for coronavirus, back to the ward at St Thomas’ Hospital in London.
Earlier, No 10 said the PM “continues to improve” after a “good night” and thanked the NHS for the “brilliant care” he has received.
The weekly “claps for carers” have been providing “wonderful, unifying moments” for the country, while it is hoped millions will turn out again at 8pm, his spokesman added.
Mr Raab was expected to instead take part in the show of support for health staff.
The Foreign Secretary, appearing at the daily press conference, said he had not spoken to Mr Johnson as it was important to let him focus on his recovery.
“We in the Government have got this covered. I chaired the Cobra meeting that I have just come from, we are pursuing all the different strands of our strategy to defeat the coronavirus and I’m confident we’ll get there.”
Mr Johnson was last seen in public clapping for NHS workers in Downing Street last Thursday before his admission to hospital three days later.
Chancellor Rishi Sunak announced the first big breakthrough in Mr Johnson’s health on Thursday, when he said the PM was now “sitting up in bed” and “engaging positively” with medics.
Concerns have been raised over Dominic Cummings, the PM’s chief adviser, who has been self-isolating with coronavirus symptoms.
Ten days after Downing Street confirmed his symptoms, the PM’s official spokesman was unable to say Mr Cummings is working, instead saying he is “in contact with Number 10”.