British PM Boris Johnson says he is “deeply sorry” as the country tops 100,000 coronavirus deaths – the worst tally in Europe and the fifth nation in the world to reach that “grim statistic”.

In March 2020, Britain had hoped to cap deaths from the pandemic at 20,000.

But as a devastating second wave pushes hospitals to the brink, the country faces even more heartache in coming weeks.

At a media conference addressing the horror milestone, Mr Johnson took full responsibility as he promised to honour every life when the crisis was over.

“I am deeply sorry for every life that has been lost and, of course, as Prime Minister, I take full responsibility for everything the government has done,” he said.

“We truly did everything we could and continue to do everything we can to minimise loss of life and to minimise suffering during a very, very difficult stage in a very, very difficult crisis for our country.”

Britain is the fifth nation after the US, Brazil, India and Mexico to surpass 100,000 COVID deaths and it has the world’s highest number of deaths proportionate to population.

On Tuesday (local time), the country reported a further 1631 deaths and 20,089 cases, according to government figures. In one bright sign, the daily infection tally was down from 22,000 the previous day.

Experts say the government’s slowness to react – especially its delays in imposing restrictions to curb surges – has contributed significantly to Britain’s struggle with the virus.

The decision to relax restrictions for Christmas – only to tighten them again at the 11th hour – has been blamed for the current spike.

The government was also slow to act on borders. It closed travel corridors with 60 countries on in recent days.

The country is pushing to speed up vaccination delivery as it battles to keep variants of the virus at bay.

Britain was the first country in the world to approve and begin rolling out the Pfizer vaccine. Already more than 6.8 million people have received their first dose and more than 472,000 have had their second jab.

The current death toll of 100,162  is more than the country’s civilian toll in World War II and twice the number killed in the 1940-41 Blitz bombing campaign, although the total population was lower then.

“My thoughts are with each and every person who has lost a loved one – behind these heart-breaking figures are friends, families and neighbours,” Health Minister Matt Hancock said.

“I know how hard the past year has been but I also know how strong the British public’s determination is and how much we have all pulled together to get through this.”

England re-entered a lockdown on January 5. It includes the closure of pubs, restaurants, non-essential shops and schools to most pupils.

England’s chief medical officer, Professor Chris Whitty, said the high infection rate was flattening but it was too early to relax.

“It looks like it’s coming down slightly in some areas, but in others it’s not convincing,” he said.

“The number of deaths has flattened out on a very high level.

“We need to be realistic that that number will come down relatively slowly over the next two weeks.”

Opposition Labour Party leader Sir Keir Starmer said the death toll was a national tragedy and a “terrible reminder of all that we have lost as a country”.

“We must never become numb to these numbers or treat them as just statistics. Every death is a loved one, a friend, a neighbour, a partner or a colleague. It is an empty chair at the dinner table.

“To all those that are mourning, we must promise to learn the lessons of what went wrong and build a more resilient country.”

-with AAP