The Queen will not attend the COP26 climate change summit in Glasgow following medical advice to rest.
The 95-year-old monarch underwent preliminary medical checks in hospital last Wednesday after cancelling a visit to Northern Ireland.
She resumed public engagements on Tuesday by meeting ambassadors via video link from Windsor Castle.
Buckingham Palace said she “regretfully” decided not to attend a reception at the summit.
But the palace said she would deliver her address to delegates using a recorded video message instead.
The Queen was due to travel to Scotland as part of a string of COP26 engagements by senior members of the Royal Family including the Prince of Wales, the Duchess of Cornwall and the Duke and Duchess of Cambridge between 1-5 November.
The other royals will still attend the summit.
It is understood that the monarch very much wants COP26 to result in meaningful action on climate change from participating nations, and hopes her absence will not be used by others as a reason not to attend.
The Queen spent the night of 20 October in a London hospital before returning the next day to Windsor Castle, where she was said to be “in good spirits”.
In its latest statement, the palace said: “Following advice to rest, The Queen has been undertaking light duties at Windsor Castle.
“Her Majesty has regretfully decided that she will no longer travel to Glasgow to attend the evening reception of COP26 on Monday, 1 November.”
The statement concluded: “Her Majesty is disappointed not to attend the reception but will deliver an address to the assembled delegates via a recorded video message.”