European consumers get about a quarter of their natural gas needs met by Russia, though the bulk of those supplies run through the Soviet-era transit network in Ukraine.
Russian President Vladimir Putin last week warned European leaders that gas through Ukraine may be cut unless Kiev settles its outstanding debt to Russian gas company Gazprom.
Ukrainian Energy Minister Yuri Prodan said Monday, however, there may be enough gas in storage to stave off a gas crisis.
"Within a certain period of time, up to three months, Ukraine will be able to ensure gas transit to European countries," he said.
Gazprom in 2009 cut gas supplies to Ukraine in response to contractual disputes. The deal that ended the impasse saddled Ukraine with some of the highest natural gas bills in the region.
European energy security is at risk because of lingering geopolitical disputes over Ukraine. The U.S. State Department last week criticized the Kremlin for using energy as a political tool.