The Ukrainian government this week said testing began to send 70 million cubic feet per day from Slovakia to Ukraine through the joint work of transit companies Uktransgaz and Eustream.
Ukrainian Energy Minister Yuri Prodan hosted Slovakian Minister of Economy Pavol Pavlis in Kiev to discuss the prospects of a new relationship in the natural gas sector.
"Small reverse flow will become a basis for further collaboration between Slovakia and Ukraine," Pavlis said in a statement.
Russian energy company Gazprom in June cut gas supplies to Ukraine because of lingering contractual disputes. Most of the Russian gas sent through Ukraine heads to European consumers and the Ukrainian energy minister said his country was still a reliable transit nation.
"The Ukrainian side stands technologically ready to provide the transit of natural gas from the Russian Federation to Europe, even after termination of deliveries of Russian gas to Ukraine," he said Tuesday.
German energy company RWE in April said it reversed the flow of natural gas from Poland to supply a Ukrainian market under the Kremlin's influence.