Prince William speaks publicly for first time since King Charles's cancer diagnosis

Prince William has referenced the King's cancer diagnosis for the first time since the announcement by Buckingham Palace on Monday.

Arriving at a gala for the London Air Ambulance Service in central London, the Prince of Wales waved to people gathered outside and said: "We really appreciate everyone's kind messages, thank you."

Inside, he gave a speech and again thanked everyone for "kind messages".

With his father's diagnosis announced a week after his wife Kate, the Princess of Wales, returned home from abdominal surgery, William said the last few weeks have had a "medical focus".

"I'd like to take this opportunity to say thank you, also, for the kind messages of support for Catherine and for my father, especially in recent days," he said.

"It means a great deal to us all. It's fair to say the past few weeks have had a rather medical focus," he added, joking that he had come to an air ambulance function to "get away from it all".

Before he spoke, he was spotted talking to and laughing with Hollywood star Tom Cruise - also at the gala tonight.

He also joked about a pair of custom slippers he wore at the Top Gun: Maverick film premiere, telling the actor, who starred in the sequel: "I haven't got my Top Gun slippers on."

Cruise replied: "I miss them."

William is a former air ambulance pilot with the East Anglian Air Ambulance and during the event met crew members, former patients and supporters before delivering the speech.

The gala dinner is raising funds for London's Air Ambulance Charity's Up Against Time appeal, which is seeking £15m to replace the service's helicopter fleet by the autumn.

"By September, we need the two new red birds - decked with the latest kit such as night vision - in our skies," he said.

He also nodded to Cruise, jokingly asking the Mission Impossible star not to borrow one of their helicopters for his next film.

"We have all seen on our screens that, how can I put it, you seem to have a different take on normal wear and tear to the rest of us," he added.

Prince William was back at work supporting the King on Wednesday, when he hosted a Windsor Castle investiture ceremony.

His brother Prince Harry had been told, like other senior royals, personally by the King about his diagnosis, and quickly boarded a flight from California, spending around 45 minutes at Clarence House on Tuesday before returning on Wednesday.

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The King looked relaxed when, as he returned to Sandringham, he was seen in public on Tuesday for the first time since the diagnosis was announced.

His treatment as an outpatient started earlier this week and he has postponed all public-facing duties, although he is continuing with work on his red boxes of state papers.

His weekly private audience with the prime minister is planned to be held over the phone, rather than in person.

It is understood this is expected to revert to in-person meetings in two weeks.

William is expected to take on more public duties while his father focuses on treatment.