Ukraine warns EU of 'full-scale' Russian attack

He urged the EU to put “diplomatic pressure” on Moscow to return to US and EU-mediated peace talks in the so-called Geneva format.

He urged it to impose “a new wave” of preventative sanctions, such as blacklisting more Russian officials and raising the “economic … cost” of Russia's actions.

He also accused Moscow of trying to undermine the political process in Kiev in order to make Ukraine a “failed state”, while calling on Europe to maintain “technical and financial support” in areas such as judicial and constitutional reform.

Yelisieiev’s warning comes ahead of the first meeting of EU foreign ministers, on Monday, to be chaired by the bloc’s new foreign policy chief, Federica Mogherini.

Mogherini’s spokeswoman, Maja Kocjiancic, told EUobserver that Ukraine will be “one of the main topics” of discussion.

“It’s important that peace efforts continue ... there will be a political debate about the situation on the ground and the EU response”.

Mogherini herself earlier said the ministers might expand EU blacklists on Russia but that talk of further economic sanctions will wait for December’s EU summit.

Fresh assessments by the US and by Nato corroborate Yelisieiev’s warning.

Speaking at the UN Security Council on Wednesday, US ambassador Samantha Power said “Russia is … surging more forces and more equipment across the border”.

She noted that since 9 November, the US has seen: 17 unmarked trucks moving toward the ceasefire line near Donetsk in east Ukraine; movements of 43 more military vehicles in the Donetsk area, some towing large-calibre howitzers and multi-launch rocket systems; and new “columns of … Russian tanks, Russian artillery, Russian air defense systems, and Russian combat troops entering Ukraine”.

US general Philip Breedlove, who is also Nato’s top military commander, echoed Power at a think-tank event, also on Wednesday, in Sofia.

“What worries me the most … is that we have a situation now where the former international border, the current international border, of Ukraine and Russia, is completely porous; it is completely wide-open. Forces, money, support, supplies, weapons are flowing back and forth”, he told press at a meeting of the Atlantic Club of Bulgaria.

He noted that pro-Russia fighters in east Ukraine control “pockets” of territory, but do not hold strategic airports and have “interrupted” lines of communication.

Ukrainian analysts also say Russia needs to create a land corridor to Crimea, which it annexed in March, but which it can only reach by sea.

In August, Russia seized the town of Novoazovsk in south-east Ukraine, creating a potential staging post for an attack on the Ukrainian-held city of Mariupol - the main obstacle for the Crimea land bridge.

Looking at the recent movements of Russian forces in Ukraine, Breedlove added: “My strategic team believes … that these forces will go in to make this [the patchwork of Russia-controlled territories] a more contiguous, more whole and capable pocket of land in order to then hold onto it long-term”.

Meanwhile, Nato secretary general Jens Stoltenberg told Germany's Bild newspaper on Friday that "in the past days ... Russia has again brought arms, equipment, artillery, tanks, and rockets over the border into Ukraine".

“Putin has clearly broken the truce agreement and has violated Ukraine’s integrity".