New Delhi, May 1 -- King Charles III and Queen Camilla visited the site of the Sept. 11 attacks, met with schoolchildren and business titans and socialized with celebrities during a busy swing through New York City on Wednesday - the first visit to the city by a reigning British monarch in 16 years.

Charles laid flowers at the National 9/11 Memorial and the royal couple spoke with victims' relatives, first responders and local dignitaries before traveling to other events midway through a four-day diplomatic trip to the U.S. to mark 250 years of American independence.

The royal couple capped their whirlwind day in the city with an appearance at an early evening reception for one of the king's charities, the King's Trust, where Charles sp...