Prince William, Duke of Cambridge and his wife Catherine, Duchess of Cambridge, lay flowers at the 9/11 Memorial in New York (AFP)
Britain's Prince William and his wife Kate visited the 9/11 memorial in the pouring rain on Tuesday, placing a bouquet at one of the reflection pools on the final day of their New York tour.
It was a somber start to the day after a night spent hobnobbing with American basketball superstar LeBron James and chatting to music power couple Beyonce and Jay-Z at an NBA game in Brooklyn.
The National September 11 Memorial is dedicated to the memory of nearly 3,000 people killed in the 2001 Al-Qaeda strikes on the World Trade Center, as well as six people who died in a first attack on the Twin Towers in 1993.
The Duke and Duchess of Cambridge paused for a moment of contemplation at one of the memorial's two reflecting pools, shielded from the chilly rain by large black umbrellas.
The names of every person who died in the 2001 and 1993 attacks are inscribed into bronze panels along the edges of the pools, which are built in the footprint of the Twin Towers.
Kate wore a double-breasted cerise wool silk coat fastened with black buttons from British luxury label Mulberry, over her customary thick black tights and a pair of classic black pumps.
Five months pregnant with her second child, she wore her hair pulled back in a sleek pony tail, and finished her look by wearing black gloves and carrying a small black clutch.
William wore a dark suit.
- 'King James' -The royal couple were greeted by 9/11 Memorial President Joe Daniels before visiting the museum, built into the bedrock of the Twin Towers and which documents the 2001 attacks, their impact and legacy.
Overlooking the site is the $3.9 billion One World Trade Center, the tallest building in the Western Hemisphere -- its glass silhouette enshrouded in low-lying clouds Tuesday.
The royal couple's lightning three-day visit -- their first to America's biggest city -- is a mix of diplomacy, supporting their favorite causes and promoting British business.
Second in line to the throne after his father Prince Charles, William is increasingly taking on more long-haul work for the British monarchy as Queen Elizabeth II approaches her nineties.
New Yorkers have welcomed the British couple with warmth and hospitality -- but also some amusement and bewilderment.
On Monday, James enthralled them with a brilliant display as he led the Cleveland Cavaliers to their seventh win in a row, defeating the Brooklyn Nets at the Barclays Center.
The four-time NBA Most Valuable Player and double Olympic gold medalist -- known as "King James" -- met the royal couple at the end of the game, giving them a Cavaliers shirt marked Cambridge and another for their one-year-old son Prince George.
- Beyonce and Jay-Z -"This very moment will be forever remembered and put up in my house. It's all good and all smiles on this side," James wrote on his Instagram page next to a photo with the royal couple.
Jay-Z and Beyonce, who sat opposite them on the other side of the court, also walked over to say hello and chat for several minutes to deafening cheers from the crowd.
It was a starstruck end to a packed day that saw William meet President Barack Obama, and the couple met widely tipped 2016 presidential contender Hillary Clinton and her daughter Chelsea.
Later on Tuesday they are expected to tour a youth organization, where they will view arts performances, before attending a lunch-time reception to celebrate creative British talent in New York.
William, and possibly his wife depending on how tired she may feel, are then expected to go up The Empire State Building, before both attend a gala dinner at the Metropolitan Museum of Art.
The banquet, where Hollywood actor Tom Hanks will reportedly make a toast, is to celebrate the 600th anniversary of St Andrews University, where the couple met and fell in love.
The couple, who are in the United States without their son, are expected to fly home after the dinner.
They are staying at the Carlyle Hotel, where William's mother Diana used to stay.
Their arrival has drawn comparisons with the 1985 visit made by Charles and Diana, when the princess dazzled Americans by dancing with US president Ronald Reagan and Hollywood star John Travolta.