LONDON, England: The British government has pledged that all adults in the country will receive their first dose of the coronavirus vaccine by July 31.

The government had earlier said all adults would be vaccinated by August 31.

Also, the government has said it will vaccinate everyone over 50 years old or with an underlying health issue by April 15.

In making the announcement, U.K. Health Secretary Matt Hancock said, "We now think that we have the supplies" to ensure such widespread vaccinations are administered.

The government reports that over 17.2 million people, nearly one-third of all adults, have received the first dose of the vaccination.

In a bid to stretch their supplies, Britain is delaying the public's receiving the second vaccination until 12 weeks after the first. Pfizer, the manufacturers of the vaccination, has said it has no data to support such a delay.

Meanwhile, on Saturday British Health Secretary Matt Hancock said the government is concerned about coronavirus mutations from Brazil and South Africa, and data needs to be carefully reviewed as the country slowly ends the nationwide lockdown.

"It is very important to see the impact of steps that we're taking. We want to set out a roadmap which gives people guidance, in terms of how we think we'll be able to do this. We also absolutely will be vigilant to the data on the way," Hancock told Sky News.

"We've currently seen other new variants. Thankfully there's very, very, very few of these in this country now, but we've got to protect against them."

Britain has suffered the highest death toll from Covid-19 in Europe, with more than 120,000 deaths.