WASHINGTON, Dec 2 (Reuters) - U.S. President Joe Biden and his wife Jill participated in the National Christmas Tree Lighting Ceremony outside the White House on Thursday, helping to usher in the holiday season. In a program that featured performances by singers Patti LaBelle, Billy Porter, and Kristin Chenoweth, the president presided over a countdown that ended with a brightly lit tree with a shining star on top. Biden said the evergreen tree "reminds us that even in the coldest, darkest days of winter that life and abundance will return." The president, who unveiled new measures to fight the COVID-19 pandemic during the winter on Thursday, cited those who had lost loved ones to the deadly coronavirus and paid tribute to members of the military and their families. "Jill and I are especially grateful to our service members and their families," Biden said. "We also keep in our hearts those who lost loved ones because of this virus or any other cruel twist of fate or accident." The Bidens are spending their first holiday season in the White House as president and first lady. Earlier this week, holiday decorations were unveiled. On Wednesday, Vice President Kamala Harris and her husband, Doug Emhoff, who is Jewish, celebrated Hanukkah with the lighting of a menorah at the White House.