UK Prime Minister Boris Johnson issued a statement on Saturday, April 11, thanking the National Health Service staff at St. Thomas' Hospital following his treatment for coronavirus, saying "I can't thank them enough. I owe them my life."

This is the first known statement from the Prime Minister since he entered the hospital last Sunday night.

Johnson announced he tested positive for the novel coronavirus on March 27. He said he was experiencing "mild symptoms" and would continue leading the country -- while self-isolating in his apartment in Downing Street.

But 10 days later, 10 Downing Street announced the 55-year-old was not getting better and was taken to St. Thomas' Hospital in London. He was moved to an intensive care unit (ICU) the next day after his condition deteriorated.

Johnson spent three nights in intensive care and received "standard oxygen treatment," according to his spokesman, but did not require mechanical or invasive ventilation.

He was moved out of the ICU on Thursday night. On Friday, a spokesman said the Prime Minister was "able to do short walks" in between periods of rest and waved his thanks to the staff.

He "is in extremely good spirits," the spokesman added.

Also read: British PM getting better in intensive care as he battles COVID-19