"Queen Elizabeth was a life well lived," King Charles III said, as he renewed his "darling Mama's" promise of lifelong service.
In an emotional first address to the nation, he praised her warmth, humour and ability to see the best in people.
Charles and his wife, Queen Consort Camilla, then spent more than 10 minutes shaking hands with dozens of well-wishers and looking at floral tributes outside the palace after getting out of their car for an impromptu walkabout.
Prince William and Catherine will become Prince and Princess of Wales, he said, as he expressed his love for his son Prince Harry and wife Meghan.
The Queen died peacefully at Balmoral in Scotland on Friday aged 96.
While the speech was being broadcast, a service to remember the late Queen got under way at St Paul's Cathedral.
Yesterday saw world leaders and people from around the globe pay tribute to Queen Elizabeth II, the United Kingdom's longest serving monarch.
In New Zealand all public buildings are flying flags at half-mast, the Army's 16 Field Regiment fired 96 rounds - one for every year of Queen Elizabeth's life at Te Papa on Wellington's waterfront last night and condolence books for people to pay their tributes have been made available throughout the country.
Tell us your Queen memories
Have you done a special tribute to the Queen today? Do you have memories of meeting her? Send us your photos and your stories at iwitness@rnz.co.nz for compilation into a future story.
See how this morning events unfolded with RNZ's blog: