Only membership of NATO would enable Ukraine to defend itself from external aggression, Ukrainian Prime Minister Arseny Yatseniuk said.
Speaking at a conference in Kiev attended by Ukrainian and European lawmakers and business leaders on Saturday, Yatseniuk made clear he did not view the ceasefire as the start of a sustainable peace process because of Putin's ambitions.
We are still in a stage of war and the key aggressor is the Russian Federation ... Putin wants another frozen conflict (in eastern Ukraine).
His goal is to take all of Ukraine ... Russia is a threat to the global order and to the security of the whole of Europe.
NATO in these particular circumstances is the only vehicle to protect Ukraine.
More top news
All of her jewellery is said to have been taken in the raid on Friday night after she left the country for her Christmas holiday.
The first day of a major new train timetable overhaul was hit by disruption as rail commuters were warned to check their journey details.
German railway operator Deutsche Bahn claimed the climate activist in fact had a seat in first class.