KIEV -  Ukraine said Friday it was seeking a compromise with nationalist activists who were cutting off coal and other trade between the ex-Soviet republic and its Russian-backed separatist east.

President Petro Poroshenko warned last week that protesters blocking a railway to the coal-rich war zone could cause power outages across the country and job losses as a result. Ultranationalists have put a stop to a railway line since the end of January that runs between the coal-producing east and the rest of Ukraine to protest against Kiev's trade with it foe.

Ukraine has declared a state of emergency in the energy sector over the blockade. Prime Minister Volodymyr Groysman said Friday the cash-starved and war-torn east European country could soon start losing electricity and heating because of the strike.

"The government's position is clear -- we are ready for dialogue, for professional talks," Ukrainian media quoted the pro-Western prime minister as saying. "But we are not ready for sabotage."

The strikers believe that the insurgents use the freight cars to shuttle fighters and weapons to hotspots in the war. They also accuse corrupt officials of allowing contraband to reach Ukraine from the east along with the specific type of coal used by the country's power plants throughout Ukraine. Groysman warned of an imminent deficit in both power and heating. He added that steel mills "that employ 300,000" people could fall silent.

"That sector comprises 12 percent of our gross domestic product," he said. "If there is a stoppage, it will mean that the strikers want to take away our opportunity for economic growth." Ukraine bounced back from a 2014-15 recession in which its economy contracted by about 17 percent to see 2.2 percent growth last year.

The trade has gone on even as Kiev and the separatists are locked in a 34-month conflict that has claimed more than 10,000 lives. One soldier was reported killed Monday while the Organization of Security and Co-operation in Europe (OSCE) mentioned a sharp de-escalation of violence in the days since a new truce went into effect on Monday.

The European security body in charge of monitoring the implementation of repeatedly broken peace deals in Europe's only war said it could not confirm that the sides had pulled backed their big guns from the front as promised. "Without the update on inventories the OSCE cannot verify the withdrawal of the weapons and the disengagement of the sides. Without these verifications the process will not work. There must be evidence. "If there is no proof and no trust, the process will break down," it said.