Britain's Kate set to attend Wimbledon men's final on Sunday

London: Kate, Britain's Princess of Wales, will attend the men's singles final at Wimbledon on Sunday, her office said on Saturday, set to mark her second public appearance since surgery six months ago revealed the presence of cancer.

The 42-year old princess, who is undergoing preventative chemotherapy, is an avid tennis fan and is patron of the All England Lawn Tennis and Croquet Club Wimbledon, which hosts the annual tennis championships.

Kate and her husband, heir-to-the-throne Prince William, also posted a message on social media on Saturday to his aunt, Princess Anne, who returned to official engagements on Friday less than three weeks after treatment for concussion sustained from a head injury believed to have been caused by a horse.

"Super trooper! So great to see you back so soon! W & C x," read their message to Anne, 73, who is the younger sister of King Charles.

Kate made her return to public duties in June at "Trooping the Colour", the annual military parade to mark the official birthday of Charles, and said she hoped to attend other events over the summer.

"I am making good progress, but as anyone going through chemotherapy will know, there are good days and bad days," she said in a personal written message ahead of last month's appearance.

"My treatment is ongoing and will be for a few more months," said the princess, often known by her maiden name Kate Middleton.

Her office, Kensington Palace, has declined to give specific details about the type of cancer or her medical condition, other than to say the treatment started in February.

Charles, 75, has also been undergoing treatment for cancer. He returned to public duties in April, and has remained busy, although his agenda commitments are being limited to minimise risks to his recovery.