British Prime Minister Boris Johnson has been admitted to hospital for tests due to persistent coronavirus symptoms, his office said Sunday.
"This is a precautionary step, as the prime minister continues to have persistent symptoms of coronavirus 10 days after testing positive for the virus," the prime minister's office said in a statement.
On March 27, Johnson said he had tested positive for coronavirus. He said on Friday he would continue to self-isolate with a high temperature.
Queen Elizabeth offered a message of reassurance Sunday evening, calling on British people to act with "self-discipline" and "good-humoured resolve" to overcome the coronavirus outbreak.
A rare speech by the 93-year-old monarch was broadcast as the country struggles with the impact of the coronavirus epidemic, which has infected 47,806 and killed 4,934 as of Sunday, according to British government data.
"I hope in the years to come everyone will be able to take pride in how they responded to this challenge," she said.
The monarch added that Britain "will succeed" in the fight against the virus and while there might be "more still to endure, better days will return."
The queen is currently in self-isolation at Windsor Castle with her husband Prince Philip and it is only the fourth time she has given such an address during her 68-year reign.
She previously gave a special address in 2002 following the death of her mother, the Queen Mother, in 1997 after the death of Princess Diana in a Paris car crash, and in 1991 about the Gulf War.
Prince Charles, the queen's oldest son and heir to the British throne, announced in late March that he tested positive for coronavirus. He has since made a full recovery.