A man looks at armed pro-Russian separatists at a town center in Snizhnye in eastern Ukraine June 12, 2014. (Shamil Zhumatov/Reuters)

In Ukraine crisis, tanks on one hand and words of peace on the other

— Words and images clashed Thursday as separatists drove three tanks across the Russian border into Ukraine, according to Ukrainian officials, and Russia’s top diplomat said the insurgents are ready for a pause in the conflict.

Ukrainian Interior Minister Arsen Avakov said the tanks and several armored personnel carriers entered eastern Ukraine through a checkpoint manned by rebels in the Luhansk region. He said government troops attacked the convoy when it reached the neighboring Donetsk region, destroying part of it. The claim could not be independently verified.

In Moscow, meanwhile, Foreign Minister Sergei Lavrov said Kiev must show its peaceful intentions before a truce can be reached. “We know that the self-defense forces in the southeast are prepared for a cease-fire, but according to the rules, the first step needs to be made by the Kiev authorities,” he told reporters.

It was not clear which pro-Russian forces he spoke for, if any. Separatist factions in eastern Ukraine have clashed with one another in addition to government forces. Lavrov’s remarks came a day after an unusual appearance in Moscow by a top Donetsk separatist leader, Denis Pushilin, who met with a Russian nationalist politician and attended a pro-separatist rally.

In a sign of the region’s tension, an explosion left a van in flames Thursday night outside the Donetsk administration building, which has been taken over by separatists. The breakaway Donetsk People’s Republic said on Twitter that the van was used by Pushilin but that he was not in it, the Associated Press reported. Four people were reported injured.

Ukrainian President Petro Poroshenko and Russian President Vladimir Putin spoke by telephone Thursday about ways to stop the violence, the Kremlin said.

There were signs that not all separatists are willing to lay down their arms. A video that appeared Thursday on YouTube showed two men, one with the brim of his hat pulled over his eyes and the other in a balaclava, vowing to “hunt” commanders of Ukrainian troops fighting the rebels. The authenticity of the video could not be verified, however.

Also Thursday, Russia seemed one step closer to cutting off the flow of natural gas to Ukraine next week, a day after negotiations over payments for supplies broke down.

If Russian state-owned Gazprom is not paid $2 billion by Monday, the energy company will take steps that would result in the cutoff of gas supplies to Ukraine, chief executive Alexei Miller said Thursday, according to the Interfax news agency.

“The stance of Ukraine is open blackmail. No constructive steps and no compromises occurred from the very beginning, and it appears to be a wish to escalate our relations in gas sector to the limit,” Miller said. “This timeline will not be moved anymore.”

Russia and Ukraine have quarreled over the price of natural gas, with Russia offering a price of about $385 per 1,000 cubic meters of gas. Ukraine says the price is high and politically motivated and has threatened to take the dispute to international arbitration. If the gas supplies are cut off Monday, analysts say, Ukraine still has enough stored gas to last for at least two months, but the risk is that a cutoff could create a Europe-wide shortage this winter if not enough gas is pumped into Ukrainian storage tanks ahead of time. Ukraine is a key transit point for Russian gas supplies to Europe.

Birnbaum reported from Moscow.