BOSTON - Prince William greeted U.S. President Joe Biden at Boston's waterfront on Friday, the final day of a visit by British royals trying to focus attention on tackling environmental issues.

William and his wife, Kate, attempted to keep the spotlight on climate and other causes they champion on their first overseas trip since taking on the titles of Prince and Princess of Wales after the death of Queen Elizabeth in September.

In the middle of their U.S. visit, however, Netflix Inc released a trailer for an upcoming documentary series about William's younger brother, Harry, and his American wife, Meghan, reviving talk about rifts in the royal family. Buckingham Palace also was dealing with a new racism controversy.

On Friday afternoon, William smiled as he met Biden outdoors in cold weather along Boston's waterfront. The two men took a brief stroll before a private meeting at the John F. Kennedy Presidential Library and Museum.

The pair were expected to discuss "shared climate goals" and "prioritization of mental health issues," White House spokeswoman Karine Jean-Pierre told reporters before the meeting.

Later on Friday, William and Kate honored winners of the Earthshot Prize, an award William established to recognize people working on solutions to problems caused by climate change.

"By supporting and scaling them, we can change our future," William said on stage at the black-tie ceremony, which was attended by English soccer star David Beckham, James Bond actor Rami Malek and other celebrities.

Kate and William last visited the United States in 2014, when they were guests of then-President Barack Obama at the White House.

Their current trip came just days before Harry and Meghan looked set to steal the limelight at an awards ceremony in New York.

For many in the British media, Harry and Meghan have become the royal villains, turning their back on duty while using their royal status to forge out lucrative careers and earn millions, including from Netflix.

In contrast, William and Kate are usually portrayed in the British media as dutiful and earnest, reflecting the style of the late queen.

(Writing by Lisa Richwine in Los Angeles, editing by Deepa Babington and Lincoln Feast.)