Boris Johnson moved to intensive care after being hospitalized with coronavirus

British Prime Minister Boris Johnson has been moved to intensive care after being admitted to the hospital with symptoms of COVID-19.

Johnson on Sunday was hospitalized 10 days after testing positive for the novel coronavirus. A spokesperson described this as a "precautionary step" after he continued to experience "persistent symptoms," and Johnson tweeted Monday that he went to the hospital for "some routine tests." Upon announcing he tested positive for COVID-19 on March 27, Johnson described his symptoms as "mild," saying they included a fever and a cough.

A day after being hospitalized, Downing Street announced on Monday afternoon that Johnson is now in intensive care at St. Thomas' Hospital.

"Over the course of this afternoon, the condition of the prime minister has worsened and, on the advice of his medical team, he has been moved to the Intensive Care Unit at the hospital," Downing Street said in a statement.

Johnson has asked Foreign Secretary Dominic Raab "to deputise for him where necessary," the Downing Street statement also said.

A report from the Times of London had previously emerged suggesting Johnson had been treated with oxygen at the hospital, while The Guardian reported it was told last week "that Johnson was more seriously ill than either he or his officials were prepared to admit, and that he was being seen by doctors who were concerned about his breathing."