LONDON -- The Duke of Edinburgh's condition has "improved considerably" since he was hospitalized during the Diamond Jubilee celebrations for his wife, Queen Elizabeth II, a spokesperson for Buckingham Palace said Wednesday.

Prince Philip, 90, will remain in London's King Edward VII hospital for a few more days while continuing to receive antibiotics treatment for a bladder infection. But he was confirmed as in "good spirits," the spokesperson added.

The duke was hospitalized Monday as a "precautionary measure," forcing him to miss the evening Diamond Jubilee Concert, a day after he joined the queen at the front of a 1,000-vessel flotilla on the River Thames.

It came amid four days of national celebrations at the queen's 60-year reign on the British throne.

The queen made no mention of her husband's condition in a public address, but said, "Prince Philip and I want to take this opportunity to offer our special thanks and appreciation to all those who have had a hand in organizing these Jubilee celebrations."

The couple's son, Edward, who visited his father's bedside Tuesday, confirmed the duke was feeling "much better" and had been watching Jubilee festivities on TV.

Asked how the queen was doing without him, Edward said, "She's bearing up but she's missing him, obviously."

Prince Philip was last taken to the hospital in December after experiencing chest pains. He was subsequently treated for a blocked coronary artery and released a few days later.