London — For the fourth time in her 68-year reign, Queen Elizabeth addressed the U.K. during a primetime broadcast Sunday, warning of difficult days to come as the coronavirus crisis intensifies across the country.

The speech was recorded at Windsor Castle, where she is currently self-isolating along with Prince Philip. The queen thanked the medical professionals of the NHS and discussed the importance of social distancing to reduce the virus’s spread.

“I am speaking to you at what I know is an increasingly challenging time. A time of disruption in the life of our country: a disruption that has brought grief to some, financial difficulties to many, and enormous changes to the daily lives of us all,” she said. “Together we are tackling this disease, and I want to reassure you that if we remain united and resolute, then we will overcome it.”

Her Majesty The Queen addresses the UK and the Commonwealth in a special broadcast recorded at Windsor Castle. pic.twitter.com/HjO1uiV1Tm

— The Royal Family (@RoyalFamily) April 5, 2020

Prime Minister Boris Johnson has been admitted to hospital for tests, 10 days after testing positive for coronavirus, Downing Street has said.

He was taken to a London hospital on Sunday evening with “persistent symptoms” – including a temperature.

It is said to be a “precautionary step” taken on the advice of his doctor, BBC writes.

The number of people who have died from coronavirus in the UK has risen by 708 to 4,313 – the highest number since the outbreak of the pandemic.

A total of 41,903 people have now tested positive for the virus in the UK, and 4,313 of those hospitalised have died.