Obama says Ukraine will face new challenges . NATO chief announces ` ` further military intervention to reinforce our collective security '' Conflicting reports on Ukrainian soldiers switching sides . Russian President Vladimir Putin says Ukraine is ` ` on the brink of civil war ''
Obama says Russia may face new sanctions . NATO chief announces `` further military measures to reinforce our collective defense '' Conflicting reports on Ukrainian soldiers switching sides . Russian President Vladimir Putin warns Ukraine is `` on the brink of civil war ''