The Princess of Wales has undergone abdominal surgery in London and will remain in hospital for up to two weeks, Kensington Palace has announced.
In a statement, the palace said the princess, 42, was admitted yesterday to The London Clinic, a private hospital in central London, for planned abdominal surgery.
"The surgery was successful and it is expected that she will remain in hospital for 10 to 14 days, before returning home to continue her recovery," the palace said.
"Based on the current medical advice, she is unlikely to return to public duties until after Easter."
The palace refused to confirm what Kate was being treated for but said the condition was non-cancerous.
Sky News understands that the surgery was routine and after she is released from hospital, the Princess of Wales will recover at home in Windsor.
The statement added: "The Princess of Wales appreciates the interest this statement will generate. She hopes that the public will understand her desire to maintain as much normality for her children as possible; and her wish that her personal medical information remains private."
The palace said they will only provide updates on the future Queen's progress "when there is significant new information to share".
"The Princess of Wales wishes to apologise to all those concerned for the fact that she has to postpone her upcoming engagements. She looks forward to reinstating as many as possible, as soon as possible," the palace added.
The couple will also not be taking part in any engagements abroad for the foreseeable future.
Any return to royal duties for the princess will be only restarted upon medical advice that she can do so, Sky's royal correspondent said.
The princess was last seen at the Royal Family's annual Christmas Day service in Sandringham.