Prime Minister Boris Johnson has written to every household in Britain urging people to stay indoors to protect the National Health Service and save lives as the UK's battle with the coronavirus intensifies.

In the letter, which is being sent out to around 30 million households around the country in the coming days, Johnson urges national unity, and implores people to stay at home and follow the rules set out by the government. 

News of the letter being sent to UK households comes just hours after the Department of Health confirmed that more than 1,000 people in the country have now died from the coronavirus.

"We know things will get worse before they get better," Johnson's letter says.

"But we are making the right preparations, and the more we all follow the rules, the fewer lives will be lost and the sooner life can return to normal."

The letter goes on to thank NHS workers and those who have volunteered to help those vulnerable to coronavirus, but urging once again that people should stay at home for all but the most essential tasks, such as food shopping, exercise, and getting medicine.

"That is why, at this moment of national emergency, I urge you, please, to stay at home, protect the NHS and save lives," Johnson says.

The letter will be accompanied by a leaflet outlining steps that citizens can take to help stop the spread of coronavirus, including guidance on handwashing, how to self-isolate, and how to help the elderly and vulnerable.

The government said that the letter will cost around £5.7 million ($7.1 million) to print and distribute to the UK's 66 million residents.

1,019 people have died from COVID-19 across England, Wales, Scotland, and Northern Ireland, as of Friday at 5 p.m., up from 759 at the previous count. 

"Patients were aged between 33 and 100 years old and all but 13 patients (aged between 63 and 99 years old) had underlying health conditions," the National Health Service said in a statement about the deaths in England.

A total of 120,776 people have been tested for the virus in the UK so far, with some 17,089 cases, and around 103,000 negative tests.

Johnson himself is currently self-isolating at home in Number 10 Downing Street after testing positive for the virus earlier this week. Johnson announced that he had COVID-19 on Friday, just hours before Health Secretary Matt Hancock said that he also had the disease.

Chief Medical Officer Chris Whitty is also displaying symptoms of the disease.