The Duke of Edinburgh reportedly underwent a medical procedure for a pre-existing heart condition on Wednesday, March 3, Buckingham Palace confirmed in a statement.
"His Royal Highness will remain in hospital for treatment, rest and recuperation for a number of days," the statement read, and the procedure was "successful."
Prince Philip was first admitted to King Edward VII Hospital on February 16 "after feeling unwell," as "a precautionary measure”
The 99-year-old was then moved to St. Bartholomew’s hospital on Monday, March 1, to continue treatment for an infection and to undergo tests and observation for his heart condition.
"The Duke remains comfortable and is responding to treatment but is expected to remain in hospital until at least the end of the week," the Palace stated at the time.
Earlier this week, the Duchess of Cornwall said that her father-in-law was "slightly improving" but his treatment hurts "at moments."
Last week, his youngest son, Prince Edward, said that he spoke to Philip "the other day." He added, "He's a lot better thank you very much indeed, and he's looking forward to getting out, which is the most positive thing."
Prince Charles was allowed to visit his father briefly on February 20.
Meanwhile, a source told The Royal Observer that Prince Harry was recently "being advised to fly home right now to say goodbye to his grandfather." However, the insider added, "Who knows if he will listen."
Since Philip began getting medical attention last month, this has been the longest hospital stint for the Duke of Edinburgh since he was released from hospital in 2013 after 11 days when he had surgery on his abdomen.
The Duke’s heart condition is unknown, but he has reportedly had heart trouble in the past; he was rushed to the hospital in 2011 after experiencing chest pains and had a blocked coronary artery, the New York Post reported.
Prince Philp’s infection is not believed to be related to COVID-19, as both he and Queen Elizabeth II had their COVID-19 jabs already due to their ages.
The Queen is "leaning on her loved ones for support" during this time, a source told Us Weekly, as the palace prepares for Harry and Meghan's tell-all interview with Oprah Winfrey airing this weekend.
The insider added, "It’s a lot to take on. But as usual, Elizabeth is handling the stress and sadness with great dignity."