First Lady Michelle Obama will meet Samantha Cameron as part of her visit to support Team USA's efforts at the Olympics.
The pair will have a private meeting before the First Lady spends the rest of the day cheering on her nation's athletes at events that have not yet been announced.
Mrs Obama is leading the US presidential delegation and enjoyed a ringside seat at Friday night's jaw-dropping opening ceremony.
She told youngsters on Friday that being an Olympian is not just about winning gold medals and setting records, as she urged them to stay healthy and "believe" in themselves.
Speaking at a Let's Move! event at the US ambassador's residence at Winfield House, Regents Park, Mrs Obama told gathered children that Olympic athletes are not just born, but work hard for success and refuse to give up.
Let's Move! is an initiative created by the First Lady in a bid to combat childhood obesity within a generation.
Around 1,000 American and British children took part in the activities, joining in at sports such as basketball, tennis and football, and meeting US and UK athletes including US sprinter and multiple Olympic champion Carl Lewis and Manchester United legends Denis Law and Peter Schmeichel.
Mrs Obama told the youngsters that many Olympians started out like them, "just playing".
"What they did do is they stuck with it," she said. "When they got tired and frustrated or fell short, they didn't give up. The stories of these athletes reminds us that being an Olympian is not just about winning a gold or setting a record.
"It's about pushing yourself and believing in yourself and refusing to give up. Tell yourself that time and time again. No matter what obstacles you face, keep pushing."