King Charles has held audiences with five prime ministers as foreign dignitaries begin to arrive in the UK ahead of the Queen's funeral on Monday.
His Majesty met Canadian PM Justin Trudeau; Australia leader Anthony Albanese; The Bahamas' prime minister, Philip Davis; Andrew Holness, the PM of Jamaica, and Jacinda Ardern, prime minister of New Zealand.
The audiences were held in the 1844 room at Buckingham Palace.
After signing a book of condolence at Lancaster House, Mr Trudeau tweeted: "Her Majesty Queen Elizabeth II served for her entire life, and bore the weight of her duties with impeccable grace.
"Sophie and I are in London for Her Majesty's funeral - and today, we marked the solemn occasion by signing the book of condolence."
Mr Albanese said he and his partner, Jodie Haydon, were "thankful to be here paying our respects to the Queen for her services to duty, faith, family and the Commonwealth".
Mr Davis said his conversation with the King was a "great reflection on the relationship the Royal Family has shared with the people of the Bahamas".
Many other overseas politicians will be at the funeral in Westminster Abbey on Monday.
On Saturday morning, the King held an audience at the palace with military chiefs, who have provided thousands of armed forces personnel to take part in the pageantry surrounding the Queen's funeral.
Troops will also line crowd-packed roads.
In the early afternoon, King Charles held a reception for Commonwealth governors-general, when he was joined by the Queen Consort and the Prince and Princess of Wales.
With Her Majesty's funeral imminent, the King also met Metropolitan Police Commissioner Sir Mark Rowley.
The new monarch was briefed by Deputy Assistant Commissioner Jane Connors and Commander Karen Findlay, who are leading police operations around London.
And home secretary Suella Braverman and London Mayor Sadiq Khan were also present.
Later on Saturday, US President Joe Biden is set to arrive in the UK ahead of the funeral. A planned meeting between Mr Biden and Prime Minister Liz Truss has been cancelled and the two leaders will instead hold a "full bilateral meeting" at the UN General Assembly on Wednesday.