The setting will be the Eden Project, a local tourist attraction that features a cluster of domed biomes — which will help to underscore the environmental emphasis of the summit.
Jill Biden and Catherine are also scheduled to meet at a separate engagement on Friday.
When the first lady was asked Thursday about meeting the queen, she said it would be “an exciting part of the visit for us.”
In a tweet on Thursday, the first lady said, “We are holding the entire Royal Family in our hearts today, and wishing them peace and comfort on what would have been Prince Philip’s 100th birthday.”
Philip, the queen’s husband and long-serving consort, died in April.
Buckingham Palace had previously only announced that the queen would meet the Bidens on Sunday at Windsor Castle, after the conclusion of the three-day summit.
Elizabeth has met 12 serving U.S. presidents — every one from Harry S. Truman to Donald Trump, with the exception of Lyndon B. Johnson.
Charles, the heir to the throne and an outspoken advocate for the environment, will also host a reception on Friday for G-7 leaders and business executive, focused on what he has called a “game-changing opportunity” to establish public-private partnerships that are “absolutely vital if we are to win the battle to combat climate change and biodiversity loss.”