The outgoing and incoming U.S. presidents had different messages for the Christmas holiday on Wednesday, with Democrat Joe Biden urging Americans to reflect and unite, while Republican Donald Trump offered a holiday greeting and then took aim at his political opponents.

Biden signed a bill making the bald eagle America's national bird, child abuse legislation backed by Paris Hilton, and more.

Despite the widespread celebration of Christmas Eve, it is not among the 11 recognized federal holidays in the United States,