Prince Harry worked with Aids orphans in Lesotho before joining the Army
Prince Harry is to visit the site of New York's World Trade Center on his first formal overseas engagement.
Harry, 24, will pay his respects to the victims of the 2001 terrorist attacks and meet wounded US war veterans, St James's Palace announced.
He will also play a polo match in the city to raise funds for his Sentebale charity, supporting orphans in Lesotho.
The two-day trip at the end of the month will be Prince Harry's first visit to the US since he was a child.
Prince Harry will meet families of those killed in the 11 September terror attacks at the site where the twin towers once stood.
He will then commemorate the 67 UK victims by formally naming the British Garden at Hanover Square, before meeting more families at a reception.
Sir Alan Collins, UK consul-general in New York, said the trip would reinforce strong commercial, cultural and historical links between New York and the UK.
"Prince Harry is well-known and respected in the United States of America for having deployed alongside US forces in Afghanistan," he said.
That would add additional poignancy to his visit to the World Trade Center, he added.
Prince Harry will also tour the Veterans Affairs Medical Centre in Manhattan, to see prosthetics facilities and a clinic for treating post-traumatic stress disorder.
A young British serviceman who was wounded in Afghanistan will join the prince on this part of the visit.
On 30 May, the second day of the trip, Prince Harry will take part in a polo competition on Governors Island.
The match will raise funds for American Friends of Sentebale - supporting the prince's African charity.
Prior to that he will meet Prince Seeiso of Lesotho, a co-patron of the charity, and visit the Harlem Children's Zone, a school and support centre for youngsters.
Prince Harry will travel on scheduled flights to and from New York, paid for by the Queen, the prince's private secretary Jamie Lowther-Pinkerton said.