Boris Johnson admits UK could have done things 'differently' in coronavirus response

UK Prime Minister Boris Johnson says scientists were originally not aware of the extent to which COVID-19 was being transmitted by asymptomatic people.

Prime Minister Boris Johnson during a visit to Tollgate Medical Centre in Beckton in East London. Source: AAP

British Prime Minister Boris Johnson says there were open questions as to whether lockdown was introduced too late, as COVID-19 was poorly understood in its early stages.

Asked whether lockdown came too late, Johnson said: "When you listen to the scientists, the questions that you've just asked are actually very open questions as far as they are concerned.

"This was something that was new, that we didn't understand in the way that we would have liked in the first few weeks and months, and... the single thing that we didn't see at the beginning was the extent to which it was being transmitted asymptomatically from person to person," he told the BBC.

The estimated COVID-19 reproduction number for the UK as a whole remains at 0.7-0.9, the government said on Friday, indicating that the prevalence of the virus continues to drop although the range is slightly higher in England at 0.8-1.0.

The prime minister also spoke of "lessons to be learned" and said ministers could have done some things "differently".

The current growth rate is between -4 per cent and -1 per cent, meaning the number of new infections is shrinking by between 1 per cent and 4 per cent every day, the government said.

The number of people in the UK infected with COVID-19 now stands at about one in 2000 people who are not in hospitals or care homes, the Office for National Statistics said on Friday.