WASHINGTON (Reuters) - U.S. President Barack Obama told Russian President Vladimir Putin on Saturday that Moscow's deployment of Russian forces into Crimea is a clear violation of Ukraine's sovereignty and warned of greater economic and political isolation if they are not withdrawn.
The White House said Obama and Putin spoke by phone for 90 minutes, their second phone call in the past eight days over Ukraine, an escalating crisis that is presenting a new challenge to already strained U.S.-Russian relations.
