Prince Harry and Meghan Markle's two children are yet to be named prince and princess after the death of their great-grandmother.
Archie could assume the title of HRH Prince Archie of Sussex, while his younger sister, Lilibet, could become HRH Princess Lili of Sussex.
But the youngsters still remain a plain Master and Miss on the Royal Family's website.
As the children of a son of a sovereign, they are technically now a prince and a princess, according to rules set out by King George V in 1917.
Neither the Duke and the Duchess of Sussex, nor Buckingham Palace have said if their titles will be changed.
Meanwhile, Prince William's title in the long line of succession as the Prince of Wales was quickly added with his three children now listed as 'of Wales'.
Much has been said about Archie and Lili's titles since their parents stopped using their HRH styles in January 2020 when they stepped down as senior royals.
Since then, the new King Charles III has had a publicly fraught relationship with his youngest son Harry.
But in his first address, the new monarch acknowledged the couple, saying: 'I want also to express my love for Harry and Meghan as they continue to build their lives overseas.'
His words part of the pre-recorded speech were seen as 'an olive branch' to the pair.
The King's spokesperson said about the change in titles: 'While the website was updated for the Waleses, clearly updating love on a website doesn't quite work so we've not quite done that but clearly he does love them.
'We will be working through updating the website as and when we get information.'
Asked whether Archie and Lili would take the titles of prince and princess, he said: 'At the moment, we're focused on the next 10 days and as and when we get information, we will update that website.'
In 2021, it was suggested Charles would try to prevent Archie becoming a prince in the future as part of his plan for a 'slimmed-down' monarchy.
But it is unlikely he would make such a move which would be considered greatly damaging to his relationship with the Sussexes.
To do so, the King would have to issue a Letters Patent amending Archie's right to be a prince and Lili's right to be a princess.
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