Prince Philip, the husband of Queen Elizabeth II, is being treated for an infection and is not expected to leave the hospital for several days, according to an update from Buckingham Palace on Tuesday.
"The Duke of Edinburgh remains at King Edward VII's Hospital where he is receiving medical attention for an infection. He is comfortable and responding to treatment but is not expected to leave hospital for several days," the palace said in a statement.
Prince Philip was taken to the hospital last Tuesday after "feeling unwell," Buckingham Palace said.
On Monday, his grandson, Prince William, said the 99-year-old was doing "OK" and hospital staff were "keeping an eye on him."
Prince William made the remarks during a visit to a vaccination centre in Norfolk, England, on Monday.
On Tuesday, Prince Philip's youngest son, Prince Edward, told the UK's Sky News that he recently spoke to his father, who is doing "a lot better" and is looking forward to returning home.
Prince Edward said the family was still keeping their "fingers crossed" for his father.
"We've had some brilliant and lovely messages from all sorts of people. And we really appreciate that and so does he. I've been passing them on," said Prince Edward.
Prince Philip, who turns 100 in June, stepped back from public life in 2017 and has been taken to the hospital several times in recent years. In December 2019, he received hospital treatment for a pre-existing condition.
His latest admission was not an emergency, according to a royal source, who said he travelled to King Edward VII Hospital by car and walked in unaided. The source added that the illness was not Covid-19 related.
Prince Philip and Queen Elizabeth have both received at least one dose of a Covid-19 vaccine.
The couple spent most of the past year at Windsor Castle, having moved away from Buckingham Palace during the first wave of the Covid-19 pandemic in spring 2020.
text by Max Foster and Jack Guy, CNN