Updated

German utility company RWE AG says it has started supplying gas to Ukraine, which faces delivery cut-off from its main source Russia.

RWE said in a statement that the reverse-flow deliveries via Poland began Tuesday and foresee the supply of up to 10 billion cubic meters of natural gas a year.

The company said it is the first supplier in Western Europe to deliver gas to Ukraine's state energy company Naftogaz this year. RWE previously supplied it with 1 billion cubic meters of gas in 2013.

RWE says "further significant volumes could be delivered to Ukraine if various transport restrictions at the Slovakian/Ukrainian border are politically and technically resolved within the next weeks or months."