President Barack Obama's Hawaii vacation: Day 10

President Barack Obama is seen through the window of his motorcade vehicle as he is driven through the Kailua, Hawaii, neighborhood where he is spending his annual holiday vacation with his family, Monday, Dec. 30, 2013, en route to Makiki Valley Loop Trail in Honolulu to hike with family and friends. The first family is in Hawaii for their annual holiday vacation. (AP Photo/Carolyn Kaster)

KAILUA, Hawaii (AP) — How President Barack Obama spent Day 10 of his holiday vacation in Hawaii on Monday:

— RUSSIA SECURITY: White House officials said Obama was briefed Monday on back-to-back deadly attacks in Russia as the country prepares to host the Winter Olympics in February. At least 31 people were killed in the separate explosions at a railway station and on a bus in Volgograd, which lies about 400 miles away from the site of the 2014 Winter Olympics.

A White House spokeswoman said Monday the United States would welcome "closer cooperation" with Russia on security preparations for the games.

— GYM: Obama did his usual morning workout at Marine Corps Base Hawaii, spending roughly one hour at the gym.

— GOLF: Donning a white shirt and a baseball cap, Obama played a round of golf at Royal Hawaiian Golf Club in Kailua, a scenic course at the foot of the Koolau Mountains. Obama — golfing for the sixth time on this trip in 10 days — played with six friends.

— CAMPAIGN NOTE: Obama's campaign arm, Organizing for Action, sent an email to supporters with the president's first name at the bottom saying the nation was turning a corner on health care Jan. 1 and "never going back."

— FAMILY HIKE: After a quick trip back to his vacation rental, Obama and the first family went for a hike with friends along Makiki Valley trail, a 1.1-mile trail that connects with two others to form a loop.

— DINNER: The president and Michelle Obama dined at Alan Wong's, a well-known Hawaii cuisine restaurant in a plain-looking office building.