UK Prime Minister Boris Johnson is in intensive care battling COVID-19 after his condition took a turn for the worse, a spokesman confirmed.
Johnson, 55, was admitted to St Thomas' Hospital in London on Sunday evening (local time) with "persistent" symptoms of the virus, including a high temperature, 10 days after testing positive.
"Over the course of this afternoon, the condition of the Prime Minister has worsened," the spokesman for 10 Downing Street (Number 10) said in a statement, issued on Monday night (local time).
"On the advice of his medical team, he has been moved to the intensive care unit at the hospital.
"The PM has asked Foreign Secretary Dominic Raab, who is the First Secretary of the State, to deputise for him where necessary.
"The PM is receiving excellent care, and thanks all NHS staff for their hard work and dedication."
As reported by Sky News, Johnson remains conscious and has been moved to the ICU as a precaution in case he requires ventilation.
Johnson's doctor called the Prime Minister's hospitalisation on Sunday a "precautionary step". It was reported that Johnson was required to undergo further testing.
His partner Carrie Symonds, who is pregnant with their first child, has also displayed symptoms of COVID-19 but is yet to undergo any testing.
"I haven't needed to be tested and after seven days of rest, I feel stronger and I'm on the mend," Symonds said over the weekend.
"Being pregnant with COVID-19 is obviously worrying. To other pregnant women, please do read and follow the most up to date guidance which I found to be very reassuring."
Johnson started working from home following his diagnosis, claiming he had "mild symptoms" of the virus.
"But be in no doubt that I can continue, thanks to the wizardry of modern technology, to communicate with all my top team to lead the national fightback against coronavirus," he declared, urging Britons to remain at home as much as possible.
According to Johns Hopkins University's live global COVID-19 case tracker, as of Sunday (local time), the UK has more than 52,270 confirmed cases. More than 5370 COVID-19 patients have died, while 284 have recovered.
Worldwide, the virus has infected more than 1.3 million people and killed over 73,700.