PRAGUE (AP) — A top European Union official says Ukraine’s debt for gas Russia delivered between November and May remains a hurdle to reaching a deal on energy supplies between the two countries.

EU Energy Commissioner Guenther Oettinger says Russia’s state-owned gas company, Gazprom, is willing to discuss a new gas price for Ukraine on condition the country pays its existing debts first.

Oettinger says Ukraine wants to talk first about a new market-based price for gas and would only then be willing to pay its outstanding bills.

He said Tuesday that negotiators have been trying to convince Ukraine to pay part of the debt so the talks can start.

The prospect of a possible cutoff in gas supplies to Ukraine has worried EU countries that receive Russian gas piped through the country.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.