President Bush sent Christmas greetings to U.S. troops fighting the war on terrorism and to families who lost loved ones in the Sept. 11 attacks. "America grieves with you," he said.

"During this time of conflict and challenge, Christmas is a day on which we celebrate hope and joy; when our thoughts turn to justice and compassion, and to a Prince of Peace born long ago," the president said during a holiday message offered to radio stations across the country.

"This is a day on which we give thanks for the wonder of God's love, for the blessings we have received, and for the families we love. And this year all of these things seem particularly important," the president said.

Bush was celebrating Christmas at the Camp David presidential retreat outside Washington. He and his wife, Laura, were joined by several family members, including her mother, Jenna Welch, and Bush's parents, former President George Bush and Barbara Bush. The Bushes' twin daughters, Barbara and Jenna, also were coming for Christmas.

"This Christmas finds many facing hurt and loss, especially the families of terror victims and of our young me killed in battle. America grieves with you, and we hope you'll especially find the comfort and hope of Christmas," the president said.

Bush also telephoned nine men and women in the military to pass along his best wishes and to thank them for their service, said White House spokesman Scott Stanzel. The president and his family were to attend church services at a Camp David chapel.

Shirley Warshaw, a political science professor at Gettysburg College in Gettysburg, Pa., said presidents rarely give radio addresses on Christmas.

"Generally the nation is in less stressful situations at Christmas," she said. "All the president is doing is continuing that Roosevelt tradition of bolstering the American spirit in times of American stress."

Bush taped the message before departing for Camp David on Saturday. He plans to fly to Texas on Wednesday to vacation at his Crawford, Texas, ranch.

"Laura and I send our good wishes to all the families in America that have come together in celebration. We're especially grateful to all the men and women of our military, many of whom are today separated from their loved ones because they're serving our country," he said.

"Even in this time of war, we pray for peace on earth and goodwill toward men, and we continue to ask God's blessings on the United States," he said. "Merry Christmas, and happy New Year."