WASHINGTON - President Bush made Christmas Eve calls to 10 U.S. troops serving in Iraq, Afghanistan and other spots around the world, thanking them for their sacrifice and wishing them a happy holiday even though they'll be far away from their families and friends.

The president made his calls yesterday from the Camp David presidential retreat in the Maryland mountains, where he is spending Christmas. He spoke with members of the Army, Navy, Marines, Air Force and U.S. Coast Guard, including seven serving in Iraq.

White House press secretary Dana Perino said Bush knows it is difficult for the children of U.S. servicemen and women to understand why their fathers and mothers cannot be home for the holidays.

Bush said that when the children are older, he hopes they'll understand and appreciate their parents' sacrifice, Perino said.

"He said he couldn't thank them enough for their contribution to their country, hopes they are in high spirits, and that they are serving a cause that is very noble," Perino said. "He said, 'I know that you miss your family.' "

Bush also exchanged holiday greetings on the phone with Russian President Vladimir Putin and spoke with Turkish Prime Minister Recep Tayyip Erdogan.

National Security Council spokesman Gordon Johndroe said that Bush and Erdogan discussed their efforts to fight terrorism and the importance of the United States, Turkey and Iraq working together to confront the PKK. The PKK, or Kurdistan Workers' Party, has fought for autonomy in Turkey's predominantly Kurdish southeast since 1984.

Bush will leave Camp David tomorrow for his Texas ranch and will return to Washington on New Year's Day. On Jan. 8, he begins a trip to the Middle East with stops in Israel, the West Bank, Kuwait, Bahrain, the United Arab Emirates, Saudi Arabia and Egypt.

Among those joining the president at the wooded compound in Maryland's Catoctin Mountains are Laura Bush's mother, Jenna Welch; the first couple's twin daughters, Barbara and Jenna; the president's sister, Doro Bush Koch, and her family; and the president's brother, Marvin, and his family.