Estranged British royal Prince Harry and his American wife Meghan said Friday they wished "health and healing" to Catherine, Princess of Wales, after she revealed she has cancer.

The statement came after Catherine -- known widely as Kate -- announced she has an undisclosed form of the disease and is in the early stages of chemotherapy.

"We wish health and healing for Kate and the family, and hope they are able to do so privately and in peace," said the California-based couple.

The news of Kate's diagnosis comes at a tumultuous time for relations inside Britain's royal family.

Harry and Meghan, known formally as the Duke and Duchess of Sussex, are no longer working royals, having stepped back from duties amid recriminations over the way they say they were treated by "The Firm."

They moved to California in 2020, where they live in an exclusive enclave outside Santa Barbara, and are now forging their own businesses, after being cut off from the royal purse.

Harry, who married former actress Meghan in a fairytale wedding in 2018, was at one time very close to William, but relations have soured in recent years.

The brothers have reportedly not spoken in months after Harry's public criticism of his family.

Harry has repeatedly aired complaints about the way he feels he and his wife were mistreated during their time as working royals, culminating in January 2023 with his autobiography "Spare".

In the best-seller he laid bare years of family feuding, including alleging that William physically attacked him during an argument about Meghan.

The publication followed a string of high-profile interviews and a six-hour Netflix docu-series in which Harry and Meghan repeatedly criticized the royals.

In comments that were widely seen as damaging to the monarchy, Meghan, who is mixed race, also told US chat show queen Oprah Winfrey in 2021 there had been questions before son Archie's birth about the color of his skin.

The claim prompted William to furiously respond that the royals were "very much not a racist family." 

The couple have made infrequent visits to the UK since relocating to the United States, including for the funeral of Harry's grandmother Queen Elizabeth II in September.

In a rare joint outing, tensions were visible when Harry and Meghan accompanied William and Kate on a walkabout at Windsor Castle to review floral tributes for the late monarch.

Harry was once a popular member of Britain's royal family, long seen as a breath of fresh air in the stilted institution; a young man who got himself into very human scrapes and was open about his mental health struggles.

His marriage to Meghan was an enormous event, and the couple were initially warmly welcomed by the public.

But sentiment turned when stories began to emerge of Meghan's diva-like behavior, which detractors said had fueled Harry's grievances.

The couple have also been criticized for proclaiming their desire to break with the royal family while apparently still trying to cash in on the brand, including in their latest venture, which appears to be selling homeware.