PARIS (TIP): The United States warned Russia on june 26it had only “hours” to prove it was helping disarm Ukrainian insurgents whose separatist drive has reopened a Cold War-style chasm in East-West ties. US Secretary of State John Kerry’s warning came a day before Ukraine’s President Petro Poroshenko signs the final chapters of an historic EU accord that nudges his country toward eventual membership and pulls it firmly out of Russia’s reach.

Poroshenko also intends to get German Chancellor Angela Merkel and French President Francois Hollande to join him for a second round of telephone diplomacy with Russian President Vladimir Putin in two days. Putin came under intense pressure from both European leaders and US President Barack Obama on Wednesday to rein in separatist fighters over whom he denies exerting control.

Obama said sweeping economic sanctions were imminent unless the Kremlin stopped “the flow of weapons and militants across the border”. US Secretary of State John Kerry was even more explicit in Paris on Thursday following talks with French counterpart Laurent Fabius.

“We are in full agreement that it is critical for Russia to show in the next hours, literally, that they’re moving to help disarm the separatists, to encourage them to disarm, to call on them to lay down their weapons and to begin to become part of a legitimate process,” Kerry said. The State Department added that sanctions would be also discussed by EU leaders on Friday when they sign the full Association Agreement with Ukraine that was ditched by the ousted pro-Russian president in November and now lies at the heart of the raging crisis.

The punitive steps under deliberation would target Russia’s financial and defence sectors at a time when its export-dependent economy is on the verge of slipping into another recession. US media reports said one particularly painful step under consideration would prohibit the export of technology that could help Russia explore for oil and gas in the Arctic — a major ambition of powerful stateheld energy firms.

But 11 weeks of fighting that has already claimed more than 435 lives and brought factories in Ukraine’s economically vital eastern rustbelt to a virtual standstill continued today despite the ceasefire agreement. A spokesman for Ukraine’s “antiterrorist operation” said 10 paratroopers were wounded in rebel attacks on government roadblocks on Thursday. Ukrainian media reports said gunmen had also attacked a small airport overnight in the flashpoint village of Kramatorsk.