KIEV, April 28 – Ukraine began legal procedures to try to force Russian natural gas company to cancel its recent more than 80% hike in gas prices, Prime Minister Arseniy Yatseniuk said Monday.

The government, via the national energy company Naftogaz Ukrayiny, submitted a pre-arbitration claim to Gazprom that gives both parties 30 days to try to negotiate lower gas prices.

Should Gazprom fail to respond or to agree, Naftogaz will file a lawsuit to an international court of arbitration to legally lower the gas prices, Yatseniuk said.