US President Barack Obama gestures as he delivers remarks at "A Celebration of Special Olympics and A Unified Generation" event at the White House in Washington, July 31, 2014.
President Barack Obama voiced deep concerns to Russian President Vladimir Putin on Friday about Russia's increased support for separatists in eastern Ukraine during a telephone conversation, the White House said.
The two leaders agreed to keep open their channels of communication. It was the first conversation between the two leaders since July 17, the day when a Malaysian passenger jet was shot down over eastern Ukraine by what US officials believe was a missile launched by pro-Russian separatists.
The United States and Europe increased the pressure on Russia this week with a fresh round of sanctions.
"The president reiterated his deep concerns about Russia's increased support for the separatists in Ukraine," a White House statement on the conversation said. "The president reinforced his preference for a diplomatic solution to the crisis in Ukraine."
Obama also raised his concerns about what Washington says was a violation by Russia of the 1988 Intermediate-Nuclear Treaty designed to eliminate ground-launched cruise missiles.
© Thomson Reuters 2014