Earnest says the United States remains steadfast in its support for Turkey, a NATO ally and partner, "along with all of our friends and allies around the world, as we continue to confront the threat of terrorism."
Turkey's Justice Minister Bekir Bozdag says at least 31 people have been killed and some 147 wounded in the attack on Istanbul's Ataturk airport.
00:39 The Latest: Malaysia says airport safe, no trace of toxin19
21:02 No Signs of Terrorism in German Car Attack That Killed 1 Pedestrian, Injured 227
19:15 The worst-case scenario of the apparent nerve toxin murder of Kim Jong Nam24
11:30 Official: Suspect paid $90 to attack Kim Jong Nam31