Ukraine is ready to join trilateral talks to discuss gas issues with Russia on Dec. 9 in Brussels, Ukraine state energy company Naftogaz said on its Twitter account on Monday. The former Soviet republic has not bought gas directly from Russia since November 2015, following a breakdown in relations after Russia's annexation of Crimea and support for pro-Russian separatism in Ukraine's war-torn east. Naftogaz did not say who will take part in talks that Russian Energy Minister Alexander Novak has said he hoped would take place in the first 10 days of December. The European Union relies on Russia for about a third of its gas. More than half of that arrives via Ukraine, but since ties between Russia and Ukraine hit rock bottom, the potential for disputes over pricing and other issues has accelerated. European Commission Vice President Maros Sefcovic acts as an intermediary between Russia and Ukraine in the gas dispute, trying to minimize the risk of gas supply interruptions to Europe, especially in winter. He said last week that Russian and Ukrainian officials could meet this week to discuss gas deliveries.