Kiev: US Secretary of State John Kerry said on Thursday Russian aggression in the east was the greatest threat to Ukraine and that Washington, while seeking a diplomatic solution, would not "close our eyes" to Russian tanks and fighters crossing the border.
Speaking after talks in Kiev with Ukrainian President Petro Poroshenko, Kerry demanded an immediate commitment by Moscow to a ceasefire agreement for eastern Ukraine that it, Kiev and the pro-Russian rebels signed in Minsk last September.
"Russia needs to make its choices and those choices are not just declared by words, they have to be declared by actions. That means engaging in a series of steps that will uphold the Minsk agreement that they signed up to," he said.
"We want a diplomatic solution but we cannot close our eyes to tanks that are crossing the border from Russia and coming into Ukraine. We cannot close our eyes to Russian fighters in unmarked uniforms crossing the border, and leading individual companies of so-called separatists in battle."
A surge in fighting in eastern Ukraine in recent weeks has finally shredded any pretence that a shaky ceasefire was holding. The rebels now control several hundred square km of territory more than they did in September. Ukraine has begun calling for the West to supply it with advanced weaponry.
Russia has consistently rejected accusations from Kiev and the West, for which they say they have overwhelming evidence, that it is supplying troops and heavy weaponry to the rebels.
"We are not seeking a confrontation with Russia. No one is. Not Poroshenko, not the United States, not the European community," Kerry said. "We are very hopeful that Russia will take advantage of our broad-based, uniform acceptance of the notion that there is a diplomatic solution staring everybody in the face. That is what we want."