EU warns Americans against non-essential travel to Ukraine . ` ` There will be costs for any military intervention in Ukraine , '' President Barack Obama says . `` We are strong enough to defend ourselves , '' Americans ambassador says . Ukrainian President Barack Obama to U.S. State Department leaders There is almost no phone connectivity or Internet service across Crimea , said Ukrtelecom , which is the only landline provider . : Ukraine must avoid an escalation of violence .
EU warns Americans against non-essential travel to Ukraine . `` There will be costs for any military intervention in Ukraine , '' President Barack Obama says . `` We are strong enough to defend ourselves , '' Americans ambassador says . Ukrainian President Barack Obama to U.S. State Department leaders : Ukraine must avoid an escalation of violence .