WASHINGTON (AP) — President Joe Biden marked his first Christmas in office by making calls to military service members stationed around the world, offering them holiday wishes and gratitude for their service and sacrifice for the nation.

Joined by his wife, Jill, and their new puppy, Commander, the president on Saturday spoke via video to service members representing the Army, Marine Corps, Navy, Air Force, Space Force and Coast Guard, stationed at bases in Qatar, Romania, Bahrain and the U.S.

"As your commander in chief, I wanted to take this opportunity to say thank you, thank you, thank you," he told the service members. "We're grateful for your courage, your sacrifice, not only your sacrifice but your family's sacrifice."

Speaking from a studio set up at the White House, Biden told them they're "the solid steel spine of the nation," and emphasized the "truly sacred obligation" the nation has to care for soldiers and their families.

Jill Biden expressed empathy for the difficulties their families experience spending the holidays away from their loved ones, noting that the Bidens experienced the same when their son Beau, who served as a major in the Delaware Army National Guard, was deployed to Iraq.

The Bidens planned a relatively quiet Christmas at the White House with family. On Friday night the president and the first lady participated in Holy Trinity's Christmas Eve Mass virtually in the East Room, according to the White House, and held a pasta dinner and sleepover with their children and grandchildren, a Biden family tradition.

As the coronavirus pandemic surges anew, driven by the highly infectious omicron variant, the Bidens sought with their public appearances and statements to offer a sense of unity and normalcy in an otherwise challenging season for many.

In a Christmas statement, the Bidens praised the "enormous courage, character, resilience, and resolve" of the American people in the face of the pandemic, and offered prayers that the nation would find "light in the darkness" during a difficult season.

"During this season of joy, we are inspired by the countless Americans who are a reminder that the things we hold sacred unite us and transcend distance, time, and even the constraints of a pandemic," the Bidens said in their statement.

And the call to soldiers was just the latest Christmas tradition the two participated in, after spending Christmas eve spreading holiday cheer around Washington. On Friday morning, they visited Children's National Hospital to offer holiday greetings to young patients and their families. The president showed off photos of their new puppy and Jill read a children's book to patients.

Later, the two stopped by a Jill Biden-themed Christmas tree in the Dupont Circle neighborhood. The president hung the 2021 White House Christmas ornament amid branches decked out with photos of his wife's face, apples and small chalkboards, in homage to her teaching career.

Both answered calls to the North American Aerospace Defense Command's Santa-tracking service, speaking to parents and children about their Christmas wishlists.