At least one person in the UK has died due to Omicron variant of Covid-19, the prime minister, Boris Johnson has confirmed.

Speaking during a visit to a vaccination clinic near Paddington, in west London, Johnson said: “Sadly yes Omicron is producing hospitalisations and sadly at least one patient has been confirmed to have died with Omicron.

“So I think the idea that this is somehow a milder version of the virus, I think that’s something we need to set on one side and just recognise the sheer pace at which it accelerates through the population. So the best thing we can do is all get our boosters.”

He was also unable to rule out any new coronavirus restrictions being introduced before Christmas, ITV reports.

Amid repeated questioning, he said: “I’ve been at great pains to stress to the public that we have to watch where the pandemic is going and we take whatever steps are necessary to protect public health.”

It comes after warning that some non-urgent NHS care may be cancelled as the UK ramps up its vaccine capacity to compete with the phenomenally fast-spreading Omicron Covid variant.

Sajid Javid warned the UK is in a race against the variant after Boris Johnson issued a plea to the nation on Sunday evening, warning the public of a “tidal wave of Omicron” that could cause “very many deaths”.

The health secretary said the government is aiming to vaccinate a million people every day, starting this week, if the UK is to reach another ambitious target of having offered all eligible over 18s a booster jab before the end of the year.

But achieving that number – higher than all other previous vaccination records – will take a huge effort, with health workers facing an “incredibly difficult” challenge, according to a boss at the NHS.