The Duke of Sussex will attend the unveiling of a statue honouring his late mother, Princess Diana, at Kensington Place on 1 July on what would have been her 60th birthday.
Harry flew in from California last Friday having left his wife Meghan Markle, 39, at home in Montecito with their son Archie Harrison, two, and newborn daughter Lilibet.
COVID-19 measures mean the Duke has to self-isolate for five days before he is able to step out in public and meet fellow Royal Family members.
Harry is currently staying at his Windsor residence Frogmore Cottage which has been on loan to his cousin Princess Eugenie, 30, and her husband Jack Brooksbank since Christmas.
Prince William and Prince Harry will give separate speeches at the small event which will be held in the Sunken Garden at Kensington Palace on Thursday.
In a note on Friday, Kensington Palace said that close family of Princess Diana, members of the statue committee, the sculptor Ian Rank-Broadley, and garden designer Pip Morrison will also be in attendance.
In a statement at the announcement of the statute, the princes said they hope it will allow those who loved the princess to “reflect on her life and legacy”.
Despite the rift between the royal household and the Sussexes the Queen has repeatedly said Harry and Megha remain a much-loved part of the family.
There are hopes they could travel back to England as a family unit next spring to join the Queen’s Platinum Jubilee celebrations.
