Fighting continues to rage in eastern Ukraine amidst a worsening standoff between Kiev and Moscow. Separatist rebels have made several gains on Ukrainian forces in recent days. Ukraine says Russian troops are directly involved, with President Petro Poroshenko accusing Moscow of “direct and open aggression.” On Monday, Russia renewed calls for a ceasefire between the Ukrainian government and the separatists. But Ukraine has vowed to continue the fight, saying a ceasefire would mark a Russian victory. In a statement, the Ukrainian defense minister, Valeriy Geletey, said: “A great war has arrived at our doorstep — the likes of which Europe has not seen since World War II. Unfortunately, the losses in such a war will be measured not in the hundreds, but thousands and tens of thousands.”