While the stay-at-home order has been relaxed, Johnson affirmed that there will be "no immediate end" to the nationwide lockdown.
As of Thursday, 13,729 people have died in U.K. hospitals after testing positive for coronavirus, an increase of 861 from a day earlier.
Johnson was receiving standard oxygen treatment and breathing without any assistance, according to Dominic Raab the foreign secretary who was deputising for the Prime Minister had said.
Johnson's secretary of state for health, Matt Hancock said on March 27 he had the virus, and chief medical officer, Chris Whitty announced that he would begin self-isolation after displaying COVID-19 symptoms.
The news of Johnson's hospitalisation came on the same day as Queen Elizabeth II's rare televised message to the UK during coronavirus pandemic urgingBoris
The United Kingdom has reported 563 deaths in a day, bringing the total number of patients in the country who died in hospitals to 2,352. Some 29,474 people have now tested positive, a jump of 4,324 over the previous day, according to Al Jazeera.
The Guardian reports that in a video posted on Twitter, Johnson, confirmed he had developed mild symptoms -- 'a temperature and persistent cough' -- over the last 24 hours.
"From this evening, I must give the British people a very simple instruction -- you must stay at home," the prime minister said in his address to the nation.
"Congratulations to Boris Johnson on his great WIN! Britain and the United States will now be free to strike a massive new Trade Deal after BREXIT. This deal has the potential to be far bigger and more lucrative than any deal that could be made with the E.U. Celebrate Boris!," the US President had said in a tweet.
Johnson's Conservative Party on Friday secured a majority in the House of Commons. The victory would mean that they will plough ahead with the Brexit, dashing all chances of a second referendum over the issue.