Obama calls Merkel to 'check in' on Ukraine crisis

ABOARD AIR FORCE ONE (AP) — The White House says President Barack Obama has discussed the situation in Ukraine with German Chancellor Angela Merkel.

Obama spoke to Merkel from aboard Air Force One on Thursday as he returned to Washington from Texas.

White House spokesman Jay Carney characterizes the conversation as a "check-in" between leaders.

The call comes amid increasing concern in Europe that the Ukraine crisis could lead to a cutoff of Russian gas. Russian President Vladimir Putin has told European leaders that Ukraine's mounting debts to Moscow can threaten supplies to Europe. A large portion of Europe's gas comes from Russia through Ukraine.

The White House says that the leaders will continue their talks during Merkel's forthcoming visit to Washington. No date has been announced.