Russian state media reports Monday sources inside the European Union say they expect to hold another round of gas talks with Russia and Ukraine in September.

"A meeting on energy issues is being prepared, in particular on gas," a source in the European Union was quoted as telling Russia's state-controlled RIA Novosti. "I hope that the trilateral ministerial format will resume in September."

Last week, citing a source in the Russian Energy Ministry, RIA reported talks between Russian Energy Minister Alexander Novak and European Energy Commissioner Gunther Oettinger were scheduled for the end of August.

European leaders are trying to diversify a natural gas sector that depends heavily on Russia. Most of the gas Russia sends to Europe runs through a Soviet-era pipeline network in Ukraine and ongoing crises there add a layer of risk to the European energy sector.

No venue was announced in either report.

Russia and Ukraine are at odds over pricing formulas in a contract for natural gas. Debt disputes in 2006 and 2009 resulted in a Gazprom decision to cut gas through Ukraine, which left downstream consumers in Europe short of energy supplies.

Gazprom this year cut gas supplies to Ukraine because of lingering doubt.