Pete Souza/Official White House Photo

In keeping with tradition, President Obama called 10 service members, two from each branch of the military, to "wish them a happy holiday and thank them for their service" last night, White House spokesman Josh Earnest told reporters on the trip.

The troops are stationed around the world, he said, and the calls were placed from his vacation rental home in Kailua, Hawaii.

And, as is custom, the White House released a photo of Obama on the phone.