"God save the King" were the words with which those gathered reaffirmed the proclamation made by the clerk of the council.
The Duke and Duchess of Sussex are planning to work towards becoming 'financially independent'.
Harry, 35, was said to be desperate to be reunited with Archie, whom he had not seen for two weeks, and his 38-year-old American actress wife in Canada that the young family plans to make their home.
"The Sussexes will not use their HRH titles as they are no longer working members of the Royal Family. The Duke and Duchess of Sussex have shared their wish to repay Sovereign Grant expenditure for the refurbishment of Frogmore Cottage (believed to be 2.4 million), which will remain their United Kingdom family home," a statement from the Buckingham Palace read.
Prince Harry, the Duke of Sussex, his brother William, the Duke of Cambridge, and their father Charles, the Prince of Wales, have all been invited to the emergency meeting at the Queen's Sandringham estate in Norfolk, while Meghan, who is in Canada with the couple's eight-month-old son Archie, is expected to join the discussion over phone.
His remarks come a day after Buckingham Palace announced Harry and Meghan, who had announced their decision to step back from their royal duties, will not use the "royal highness" titles as well as would no longer receive public funds for royal duties.
The 92-year-old monarch's accounts released on Thursday showed the public funds used by her for official expenditure and duties went up from 41.9 million (Rs 377 crore to 47.4 million (Rs 426 crore).
Queen Elizabeth II may have to move out of Buckingham Palace during the much-needed repair and maintenance work to her 18th century iconic residence costing a whopping 150 million pounds, royal officials said.