Michelle Obama will lead the US delegation to the London Olympics this summer, the White House has said.
The news comes as David Cameron flies to the United States to hold talks with President Obama, where the two men are due to attend a basketball game together.
The prime minister's wife Samantha is on the trip and will host an anti-obesity event with the first lady themed around the London Games.
Mrs Obama will also meet up with school girls from Elizabeth Garrett Anderson School who are travelling from London to Washington this week.
The First Lady has kept in contact with the school after she made a surprise visit when she came to London in April 2009.
According to the Associated Press Mrs Obama will not be the first president's wife to head up an official Olympic American delegation.
Laura Bush did the same for the 2006 Winter Olympics in Torino, Italy, while Hillary Clinton led the delegation to the 1994 Winter Olympics in Norway.