Russia's state gas monopoly Gazprom says Ukraine has threatened to seize gas intended for European customers if no deal is reached on gas shipments to Ukraine starting Jan. 1.
Gazprom's deputy chairman Alexander Medvedev says Ukraine's threat amounted to "blackmail" of Russia and the European Union.
He says the threat contained in a letter from Ukraine's state gas company Naftogaz violates Ukraine's obligations under previous agreements. Medvedev showed a copy of the letter at a news conference Wednesday.
Naftogaz spokesman Valentyn Zemlyansky and other Ukrainian officials had no immediate comment.