Germany is hosting talks between Kiev and Moscow on the future transit of Russian gas through Ukraine.
Delegations from Gazprom and its Ukrainian counterpart Naftogaz were in Berlin on Tuesday, as well as Russia's energy minister Alexander Novak and Ukraine's foreign minister Pavlo Klimkin.
The negotiations were brokered by the European Commission.
European Commission Vice President Maroš Šefčovič said that talks will continue in September.
In the tensions between Moscow and Kiev, the European Union is firmly on the side of Ukraine politically. At the same time, it is is heavily dependent on Russian gas economically, especially the host country Germany. The EU receives 32% of its gas from Russia, though not all of that comes via Ukraine.
According to Thierry Bros, a researcher at the Oxford Institute for Energy Studies, this puts the EU in a tricky position.
"The question here for EU citizens is how are we going to get our Russian gas post-2019, if there is no contract?" Mr Bros told Euronews. "This is where I think the Commission has an 'enabler' position and is able to bring those two parties to the table to try to find what is going to be political and economical solution."
Russian gas piped through Ukraine to the EU brings Ukraine 3 billion US dollars a year in transit fees. But the Nord Stream 2 pipeline could transport gas directly from Russia to Germany. Gazprom has already started bypassing Ukraine. The EU wants to preserve Ukraine's financial position.
A deal needs to be reached before the current agreement expires next year on the 31st of December.
All the while Russia and Ukraine remain at loggerheads over the annexation of Crimea, which the EU continues to recognise as sovereign Ukrainian territory, and a simmering conflict in eastern Ukraine, in which Kiev accuses Moscow of meddling.