The United Kingdom is at a perilous moment in the COVID-19 pandemic, Prime Minister Boris Johnson says, adding that there were oxygen shortages in some places.
"It's a race against time, because we can all see the threat that our NHS faces, the pressure it's under, the demand in intensive care units, the pressure on ventilated beds, even the shortage of oxygen in some places," Johnson said, of the national health service.
"This is a very perilous moment," Johnson said.
"The worst thing now for us is to allow success in rolling out a vaccine programme to breed any kind of complacency about the state of the pandemic."
He said roughly 40 per cent of 80-year-olds in the country had been vaccinated already as well as 23 per cent of the elderly residents of care homes.
"It's a huge ask," Johnson said of the vaccine target.
"There's no doubt that it's a massively stretching target."
"We believe it is achievable," Johnson said.
When asked if he would tighten lockdown rules, he said people had to follow the rules.
If people failed to observe them, they may need to be tightened, he said.
"Where we have to tighten them, we will," he said of the rules.