Prime Minister Johnson is engaging with the clinical team and is sitting up in bed, UK Finance Minister Rishi Sunak said on Thursday.
He added that the prime minister remains in intensive care but his condition is improving.
On Sunday night, Johnson was hospitalised after his COVID-19 symptoms persisted following a week of self-isolation after his test for the new coronavirus came back positive. The prime minister was admitted to intensive care but, according to his spokesman, was not on a ventilator and his condition was stable.
Currently, the number of confirmed COVID-19 cases in the UK stands at 61,474, with 7,111 fatalities, according to Johns Hopkins University.
On Thursday, Foreign Secretary Dominic Raab, who has been leading the government after Boris Johnson's hospitalisation, is chairing an emergency meeting with the leaders of Wales, Scotland and Northern Ireland to discuss approaches to next week's lockdown review.