KIEV, Dec. 15 - Ukraine won’t buy any Russian natural gas this winter unless Gazprom agrees to sign an amendment to the contract, Andriy Kobolev, the head of the national energy company Naftogaz Ukrayiny, said Thursday.

“Unless the Russian colleagues accept standard terms of the contract and sign the amendment, most likely we will not be buying gas from Gazprom through the end of the winter,” Kobolev said at a press conference.