ABC News' Carolyn Durand reports:

Britain's Prince Harry, a helicopter pilot who has served in Afghanistan, paid honor to American troops today, visiting Arlington National Cemetery and laying wreaths near the grave sites of two U.S. soldiers.

Prince Harry of Wales, known as Captain Wales in the British army, visited Section 60 at Arlington National Cemetery, the burial ground for service members killed in Afghanistan and Iraq since 2001. The prince, 28, arrived dressed in his blue dress uniform with sky-blue cap and kept his hands behind his back in formal royal and military stance.

Related: Prince Harry Coming to America

Capt. Wales laid a wreath with the message, "To my comrades-in-arms of the United States of America, who have paid the ultimate price in the cause of freedom. Captain Harry Wales," near the grave sites of two U.S. Army members killed in Afghanistan in 2010. The soldiers, SPC Michael L. Stansbery Jr., and Sgt Nathan William Cox, were both awarded both Bronze Stars and Purple Hearts for their actions on the battlefield.

Prince Harry also laid a wreath at the grave site of President John F. Kennedy, the location of the eternal flame, and the Tomb of the Unknown Soldier.

Prince Harry, who entered the military in May 2005, first served in Afghanistan with the Household Cavalry of Britain's Army Air Corps in 2008, but was held back after his presence in the country was leaked because he was considered a high-value target. He returned to the country in September 2012 and completed a four-month tour of duty as an Apache helicopter pilot.

PHOTOS: Prince Harry Tours the US

The prince's visit to Arlington today struck a more somber tone than the buzz he created on Capitol Hill yesterday where work nearly came to a stop as his adoring fans, nearly all of whom seemed to be taking breaks from their Congressional jobs, waited with their iPhone cameras to catch a glimpse.

Prince Harry toured a landmine exhibit with Sen. John McCain, who called the young prince "deeply engaged," and later made a surprise visit to the White House just down Pennsylvania Avenue.

"Well surprise!" first lady Michelle Obama said as Harry, with candy in tow for military kids, arrived to the "Joining Forces" event honoring military mothers in the East Room of the White House.

From the White House, Prince Harry traveled to a place that must have felt a bit more like home, the British ambassador's residence, where he attended an evening reception honoring the 25th anniversary of Halo, the group dedicated to the removal of landmines.

Top 12 Prince Harry Revelations

"This evening gives me great personal pleasure," Prince Harry said at the reception. "My mother, who believed passionately in this cause, would be so proud of my association with Halo."

"In her own special way, she adopted it [Halo] as her own," he said, referring to his late mother, Princess Diana, who became a vocal advocate for the eradication of landmines.

Later today, Prince Harry is scheduled to visit Walter Reed Medical Center to meet with wounded veterans and tour the prosthetics and rehabilitation center. Then he will be on to Colorado Springs where he will watch the opening ceremony at the Warrior Games, an event for more than 200 wounded service personnel that will have this year, for the first time, a British team contending.

From there the prince will travel back east Monday, stopping in New Jersey and New York to tour Hurricane Sandy damage with New Jersey Gov. Chris Christie and attend a charity fundraiser.

The final leg of Harry's trip will show off his athletic skills. He'll participate in a polo match in Greenwich, Conn., to raise funds for his African charity.