In his first public comments since his diagnosis, Charles expressed gratitude to the public for their support, saying it brought him “the greatest comfort and encouragement,” according to a statement on Saturday.

King Charles III has made his first public outing since his cancer diagnosis, attending church in Sandringham alongside his wife, Queen Camilla.

The King waved to members of the public on Sunday morning as he walked with Camilla outside St Mary Magdalene Church on the monarch’s Sandringham estate in eastern England.

Around 100 well-wishers were gathered as Charles walked into the church, briefly speaking with the Rev Canon Dr Paul Williams.

Crowds gathered around the gates of the King’s private Sandringham estate, but were not allowed to enter the grounds – which are closed to the public until Easter.

It comes after the 75-year-old monarch thanked people on Saturday for their “support and good wishes” since the news of his cancer diagnosis was announced by Buckingham Palace.

Charles said all those affected by cancer knew “such kind thoughts” were “the greatest comfort and encouragement”.

On Monday, Buckingham Palace announced that the King had been diagnosed with an undisclosed form of cancer and will step back from public-facing duties while he undergoes treatment.

It was identified after Charles was admitted to a London hospital for a corrective procedure for an enlarged prostate last month, the Palace said. While the type of cancer has not been disclosed, the Palace confirmed it was not prostate cancer.

The King has stepped back from all public-facing duties while he receives treatment, with senior royals – including Queen Camilla and the Prince of Wales – taking on his duties for some events.

In his message of thanks, Charles wrote: “It is equally heartening to hear how sharing my own diagnosis has helped promote public understanding and shine a light on the work of all those organisations which support cancer patients and their families across the UK and wider world.

“My lifelong admiration for their tireless care and dedication is all the greater as a result of my own personal experience.”

Before his message on Saturday, the Queen spoke at an event at Salisbury Cathedral on Thursday and described the support as “very cheering”.

Prince William, Charles’ son and the heir to the throne, also expressed gratitude for messages of support for his father and for his wife, the Princess of Wales, as she recovers from abdominal surgery.

She is not expected to return to royal duties until after Easter.