Ukrainian Energy Minister Yuri Boiko traveled to Russia to discuss bilateral issues with Russian gas giant Gazprom, UPI cited the company as saying. Miller traveled to Moscow to meet with Gazprom Chairman Alexei Miller and "the parties discussed issues of mutual interest," Gazprom said in a statement. The company made no mention of the terms of the take-or-pay contract that covers Gazprom's natural gas deliveries to Ukraine. Gazprom recently sent Kiev a $7 billion bill for unused gas for 2012. The terms of a 2009 deal are considered too expensive by the Ukrainian government when compared with similar European contracts. European consumers are searching for ways to break the Russian deadlock on their energy sector. The vast majority of Russian natural gas bound for the eurozone is shipped through Soviet-era pipelines in Ukraine. Russia's state-run news agency RIA Novosti reported recently that U.S. State Department officials discussed the potential for shale natural gas in Ukraine during a visit to Kiev. Eastern European countries are said to be rich in unconventional natural gas deposits.