Packed agenda for Prince William, Kate in NYC, DC

NEW YORK -- Among the 5 million visitors expected in New York this holiday season, at least two are certain to get the royal treatment: Britain's Prince William and his wife, Kate. They are due to arrive today for the first trip either has made to the United States' biggest city, and William is set to visit the nation's capital for the first time.

A few things to know:

The game plan

Properly known as the Duke and Duchess of Cambridge, the royals are making their first official visit to the United States since a 2011 jaunt to California. (William made a trip to a friend's Memphis, Tennessee, wedding this May with his brother, Prince Harry.)

The couple have looked forward to a three-day trip involving issues "close to both of their hearts," a spokeswoman said.

Kate is expecting their second child in April, but the royals' schedule is packed with plans ranging from paying respects at the National Sept. 11 memorial and Museum to taking in a Cleveland Cavaliers-Brooklyn Nets game.

Other events promote British involvement in New York's technology and creative sectors and spotlight the couple's charitable interests in wildlife conservation and child development.

Among other commitments, William is set to meet with President Barack Obama at the White House on Monday while the duke is in Washington to attend a World Bank conference, where he's speaking about fighting illegal trade in wildlife parks. Meanwhile, Kate will tour a New York child development center with the city's first lady, Chirlane McCray. Former Secretary of State Hillary Rodham Clinton and daughter Chelsea Clinton are accompanying both royals to a New York reception highlighting conservation efforts.

William and Kate also are due to join Tom Hanks, opera singer Renee Fleming and others at a black-tie, $10,000-per-seat scholarship fundraiser for the University of St. Andrews, the Scottish institution where the royal couple met and earned degrees.

Traveling, with a title

The duke and duchess will take commercial flights and stay in a New York hotel, which their spokespeople wouldn't name.

Their retinue includes two private secretaries, two media aides, an adviser, a personal assistant and a privately paid hairdresser for Kate. The British government's Foreign and Commonwealth Office, the Royal Foundation -- the couple's and Harry's charity -- and St. Andrews are splitting other trip costs.

Baby watch

The couple's 17-month-old son, Prince George, isn't making the trip. Acute morning sickness sidelined Kate for a couple of months earlier this year, but she returned to her royal duties with gusto in late October.

Style guide

While the royals promote causes, many eyes will doubtless be on Kate's clothes. A style icon whose outfits can sell out in stores within hours after she's seen in them, she's won fashion-lovers' affection partly because she doesn't always choose complex or custom-made attire: "There's a connection -- you can get it," or at least a copy of it, says Michael Casey, a professor at New York's Fashion Institute of Technology.

While Kate has been known to favor such designers as British fashion house Alexander McQueen, London-based Roksanda Ilincic, the Brazilian Issa and the British upscale fashion brand LK Bennett, look for her to pack some American labels for the trip: It's a tradition to pay some fashion tributes to a host country.