A representative said he was proceeded onward the counsel of his clinical group and was accepting "phenomenal consideration".
Mr. Johnson has asked Foreign Secretary Dominic Raab to delegate "were fundamental", the representative included.
The leader, 55, was admitted to the medical clinic in London with "industrious side effects" on Sunday evening.
The Queen has been kept educated about Mr. Johnson's wellbeing by No 10, as per Buckingham Palace.
BBC political journalist Chris Mason said the executive was given oxygen late on Monday evening, before being taken to concentrated consideration.
Be that as it may, he has not been put on a ventilator.
A No 10 proclamation read: "The head administrator has been under the consideration of specialists at St Thomas' Hospital, in London, after being conceded with tireless side effects of coronavirus.
"Through the span of [Monday] evening, the state of the head administrator has exacerbated and, on the exhortation of his clinical group, he has been moved to the emergency unit the medical clinic."
It proceeded: "The PM is getting incredible consideration, and thanks to all NHS staff for their difficult work and commitment."