The Palace is expected to announce that the Queen will meet US President Joe Biden and other world leaders before the G7 summit in June.
A series of other important engagement are also thought to be in the pipeline.
Meanwhile, Palace officials are seeking to distance the Queen from the “political controversy” surrounding a proposed new £200 million national flagship.
Prime minister Boris Johnson announced earlier this year plans to commission the country’s first national flagship since the Royal Yacht Britannia was decommissioned in 1997.
It will cost up to £200m and will host ministerial summits and diplomatic talks , as well as being used on royal tours.
“But how many flagships can the Royal Navy have? Is the number limitless?
“The aircraft carrier HMS Queen Elizabeth is already the fleet flagship.
“HMS Victory, in Portsmouth Dockyard, is the First Sea Lord’s and, thus the ceremonial, flagship.”