Prince Harry lays a wreath and meets firefighters
Prince Harry has laid a wreath at the site of the World Trade Center in New York as part of his first official overseas engagement.
After observing a two minutes' silence, he was taken on a tour of the site before meeting firefighters who were involved in the rescue attempt.
He will also visit a memorial to the 67 Britons who died in the 2001 attacks.
During his two-day trip, the prince will meet wounded Iraq and Afghanistan war veterans at a medical centre.
After laying the wreath Prince Harry visited a memorial garden for the British victims.
While at the memorial he said: "It's a great privilege for me to be here today in this beautiful garden, right in the heart of New York City.
"My family are so proud to be so closely associated with it and its purpose in honouring the memory of the 67 British people who died here on September the eleventh, 2001. Thank you."
The wreath, which was made up of yellow roses and peonies, also carried a personal message signed by the Prince.
It read: "In respectful memory of those who lost their lives on September 11, 2001, and in admiration of the courage shown by the people of this great city on that day."
Monica Iken, a 39-year-old from New York who lost her husband Michael in the attacks, said she deeply appreciated the Prince's visit.
She said: "It is great he wanted to come here and show that people still care, and it shows respect to our loved ones that died on that day."
During his time in New York Prince Harry will also raise cash for his Lesotho children's charity with a polo match.
The American organisation supporting his charity Sentebale will be given the proceeds of the competition on Governors Island.
Before the game the prince will meet Prince Seeiso of Lesotho, a co-patron of the charity.
The second day of the trip will feature a visit to the Harlem Children's Zone, a school and support centre for youngsters.
BBC correspondent Laura Trevelyan, who is covering the visit in New York, said the visit had been "carefully choreographed to dispel his playboy prince image".
"Officials organising the trip hope Prince Harry's deployment alongside American forces in Afghanistan will make his public engagements poignant," she said.
"They'll also be hoping that America's enduring fascination with the Royal family will generate positive headlines for the Prince's visit."
Prince Harry is using scheduled flights to make the trip, paid for by the Queen.