Prince Harry in Washington

Prince Harry arrives at the Russell Senate Office Building to visit a photo exhibition on landmines and unexploded ordinance on May 9, 2013, on Capitol Hill in Washington. The British prince, 28, arrived in the nation's capital to begin a seven-day, six-city tour of the United States with a central theme of supporting injured service personnel from U.K. and U.S. forces.

Prince Harry, second from right, is greeted by Sen. John McCain, R-Ariz., left, as he arrives on Capitol Hill in Washington on May 9, 2013, to view an exhibition staged by the HALO Trust. Deputy Sergeant of Arms Drew Willison stands at right. The HALO Trust is a British charity dedicated to removing the debris left behind by war, in particular, landmines and unexploded ordnance that might present a danger to civilians.

Sen. John McCain, R-Ariz., left, and Prince Harry tour an anti-landmine photography exhibition by the HALO Trust charity during the first day of his visit to the United States at the Russell Senate Office Building on May 9, 2013, in Washington.

Prince Harry tours an exhibition on Capitol Hill in Washington staged by the HALO Trust, escorted by Guy Willoughby from the Trust, right, and Sen. John McCain, R-Ariz., left, on May 9, 2013.

Britain's Prince Harry tours an exhibition on Capitol Hill in Washington staged by the HALO Trust, escorted by Guy Willoughby, far left, from the Trust and Sen. John McCain, R-Ariz., right, on May 9, 2013.

Prince Harry, right, is accompanied by Sen. John McCain, R-Ariz., as he tours a Senate photo exhibit on landmines and unexploded ordnances in the Rotunda of Russell Senate Office Building in Washington on May 9, 2013.

Prince Harry tours an anti-landmine photography exhibition by the HALO Trust charity during the first day of his visit to the United States at the Russell Senate Office Building on May 9, 2013, in Washington.

Prince Harry, center, tours an exhibition on Capitol Hill in Washington staged by the HALO Trust in the Rotunda of Russell Senate Office Building in Washington on May 9, 2013.

Prince Harry, second left, listens to HALO Trust director Guy Willoughby, right, as he tours an exhibit on landmines and unexploded ordnances, escorted by Sen. John McCain, R-Ariz., left, inside the Rotunda of Russell Senate Office Building on Capitol Hill during the first day of his visit to the United States on May 9, 2013, in Washington.

Prince Harry talks with Sen. John McCain, R-Ariz., as they walk out of the Russell Senate Office Building on Capitol Hill, Washington, on May 9, 2013, after viewing an exhibition staged by the HALO Trust.

First lady Michelle Obama, center, with Jill Biden, introduces a surprise visit from Prince Harry at an event in honor of military mothers in the East Room of the White House in Washington on May 9, 2013.

Prince Harry, center, enters an event in honor of military families during a surprise visit, accompanied by Jill Biden, left, and first lady Michelle Obama, in the East Room of the White House in Washington on May 9, 2013.

First lady Michelle Obama, left, Prince Harry, and Jill Biden visit with children during a surprise appearance at an event for military mothers in the State Dining Room of the White House in Washington on May 9, 2013.

Prince Harry greets attendees before a reception in his honor at the British Ambassador's residence in Washington on May 9, 2013.

U.S. Army Col. Gregory Gadson, speaks with Prince Harry before a reception and dinner at the British Ambassador's residence on May 9, 2013, in Washington.

Sen. Roy Blunt, D-Mo., second left, speaks with Prince Harry, before a reception and dinner at the British Ambassador's residence on May 9, 2013, in Washington.

Prince Harry, along with the wife of the British Ambassador to the U.S., Lady Westmacott, greet former Sen. Max Cleland, D-Ga., before a reception in the prince's honor at the Ambassador's residence in Washington on May 9, 2013.

Prince Harry, right, speaks with British Ambassador Sir Peter Westmacott during a reception and dinner at the ambassador's residence on May 9, 2013, in Washington.

Prince Harry sits down to dinner at the British Ambassador's residence in Washington on May, 9, 2013, with Teresa Heinz, center left, wife of Secretary of State John Kerry, and the wife of the British Ambassador to the U.S., Lady Westmacott.

British Ambassador Sir Peter Westmacott toasts England's Prince Harry at a dinner at the British Ambassador's residence on May 9, 2013, in Washington.

Prince Harry, speaks at a dinner at the British Ambassador's residence on May 9, 2013 in Washington.

A card from Prince Harry is part of a wreath that he will place at Section 60 of Arlington National Cemetery, where veterans of the wars in Iraq and Afghanistan are buried, in Virginia on May 10, 2013.

Prince Harry visits Section 60 at Arlington National Cemetery on May 10, 2013. The British soldier-prince is spending most of his week in the U.S. honoring the wounded and the dead of war.

Prince Harry, right, speaks with US Army Major General Michael S. Linnington as he visits Section 60 of Arlington National Cemetery, where veterans of the wars in Iraq and Afghanistan are buried, in Virginia on May 10, 2013.

Prince Harry is accompanied by military officials as he visits Section 60 at Arlington National Cemetery in Virginia on May 10, 2013.

Prince Harry lays a wreath at Section 60 of Arlington National Cemetery, where veterans of the wars in Iraq and Afghanistan are buried, in Virginia on May 10, 2013.

Prince Harry and Major General Michael Linnington, right, salute during a wreath laying ceremony at the Tomb of the Unknowns at Arlington National Cemetery in Arlington, Va., on May 10, 2013.

Prince Harry accepts a wreath from a member of The Old Guard during a wreath laying ceremony at the Tomb of the Unknowns at Arlington National Cemetery in Arlington, Va., on May 10, 2013.

Prince Harry salutes during a wreath laying ceremony at the Tomb of the Unknowns at Arlington National Cemetery in Arlington, Va., on May 10, 2013.

Wearing his British Army uniform, Prince Harry, left, is greeted as he arrives at Walter Reed National Military Medical Center in Bethesda, Md., just outside Washington, to visit with wounded warriors on May 10, 2013.

Wearing his British Army uniform, Prince Harry visits with wounded warriors undergoing physical therapy at the Military Advanced Training Center at Walter Reed National Military Medical Center in Bethesda, Md., just outside Washington, on May 10, 2013. At right is Staff Sgt. Timothy Payne, who lost his legs in an IED explosion in Afghanistan.

Wearing his British Army uniform, Prince Harry visits with wounded warriors undergoing physical therapy at the Military Advanced Training Center at Walter Reed National Military Medical Center in Bethesda, Md., just outside Washington, on May 10, 2013.

Wearing his British Army uniform, Britain's Prince Harry, left, visits with Corey Harmon and other wounded warriors undergoing physical therapy at the Computer Assisted Rehab Environment at Walter Reed National Military Medical Center in Bethesda, Md., just outside Washington, on May 10, 2013.