KIEV, Jan. 13 - Naftogaz Ukrayiny said Tuesday that Russian gas giant Gazprom departed from its usual practice of coordinating in advance volumes of natural gas supplies to the European Union.

Naftogaz also urged Gazprom to “immediately” resume gas supplies to the EU in full to stabilize the Ukrainian gas pipeline system, which is designed for moving much larger amounts of gas.

Naftogaz issued a statement shortly after Gazprom had launched test-run supplies of its gas via Ukrainian pipelines to the EU, six days after such supplies had been suspended.