(AP) -- Britain's Prince William sat down with President Barack Obama in Washington on Monday and unveiled an effort to curtail illegal wildlife trading while his wife, Kate, made an impression of a down-to-earth duchess on preschoolers and prominent British expats in New York.

In the first full - very full - day of the popular royal couple's first visit to either place, William went to the White House and spoke at a World Bank conference. Kate wrapped Christmas gifts and helped children decorate picture frames while touring a child development center with New York City's first lady, then talked technology, theater and more with a British-success-story guest list at a lunch at the consul general's home.

The Duke and Duchess of Cambridge are on their first official trip to the U.S. since 2011. William, speaking at the World Bank, announced a new task force to develop recommendations within a year on how the transportation industry can help stop wildlife trafficking, calling it "one of the most insidious forms of corruption and criminality."

Meanwhile, the duchess and first lady Chirlane McCray met with families and heard about the work of the Northside Center for Child Development, which offers mental health and educational services.

"Very nice to meet you," Kate told a classroom of 3- and 4-year-olds, who were embellishing picture frames with stickers.

After encouraging a boy named Sammy in his work, the duchess, who is expecting the couple's second child, turned to a girl named April.

"Where should I put this one?" Kate asked, affixing a sticker.

Kate and the first lady later wrapped children's Christmas presents in the center's gymnasium, with Kate joking that she hoped she'd be given a square package to tackle.

Later, Kate chatted with lunch guests including actor Matthew Rhys, TV and theater producer Colin Callender, Parsons The New School of Design fashion dean Simon Collins and tech news site Mashable founder Pete Cashmore. She asked how Callender's recent New York staging of "Macbeth" had been received and told Cashmore his "must be such an exciting industry to be a part of."

The royals' schedule for their three-day trip includes a visit to the National Sept. 11 Memorial and Museum, a reception highlighting conservation efforts with former U.S. first lady Hillary Rodham Clinton and daughter Chelsea Clinton, a visit to showcase arts education at a youth organization, a Cleveland Cavaliers-Brooklyn Nets game and a black-tie fundraiser for their alma mater, the University of St. Andrews.

Kate, dressed in a black coat by the British fashion brand Goat, was greeted with cheers from several dozen spectators as she arrived at the Northside Center. Aaron Victor and wife Crystal Pizarro had waited almost an hour on a freezing day with their 3-year-old daughter, London, to catch a glimpse of the duchess.

"It was a very good experience, and I'm glad she got to see her," Pizarro said.

The royals are visiting a city where thousands of people have protested over the past week to decry a grand jury's decision not to indict a white police officer in the chokehold death of an unarmed black man, Eric Garner. Activists planned to demonstrate at the basketball arena while the royals took in the game.

"If the royal family is here, we want to let them know what has happened in our city," said Carmen Perez, a co-founder of Justice League NYC, a group that planned to demonstrate.

Cavaliers star LeBron James said Sunday it was possible he might wear a shirt saying "I can't breathe," a rallying cry that has developed around Garner's last words, before Monday's game.

He added that playing with William and Kate in the audience would be "a huge honor."