Russian gas bound for Europe started flowing into Ukraine, Ukrainian state energy company Naftogaz spokesman Valentyn Zemlyanski confirmed on Tuesday.
"Russian gas has started arriving in Ukraine. It is the gas bound for Europe," Zemlyanski told reporters.
Russia's gas company, Gazprom, announced on Tuesday to resume gas supplies to Europe through Ukraine.
Ukraine on Monday signed a new deal on monitoring Russian gas transit to Europe, removing conditions that Russia had opposed and clearing the final obstacle for Russia to resume gas supplies to Europe.
Russia cut off gas supplies to Ukraine on Jan. 1 after the two sides failed to reach a new deal for 2009 and resolve differences over payments due. And tensions were built up when Russia shut off all gas supplies to Europe via Ukraine on Jan. 7, accusing Ukraine of stealing gas.
Countries from Turkey to the Baltics were greatly affected by the supply cut as the Europe was experiencing an unusually cold winter.
This is not the first time the Europeans suffer from a Russia-Ukraine gas dispute. A similar dispute resulted in a briefly interrupted delivery of Russian gas to European countries in January 2006.
Russia supplies about one-quarter of the EU's natural gas, some80 percent of which is shipped through Ukraine.