BERLIN (AP) — A senior European Union official says he opposes cutting back gas ties with Russia in the next few years but the bloc should work on diversifying supplies.

Russia is a major European gas supplier, and mounting tensions over Ukraine have raised concerns about possible disruption.

In an interview with Germany's Welt am Sonntag newspaper, EU Energy Commissioner Guenther Oettinger conceded there's a risk of Russia cutting supplies to Ukraine, an important transit country, over unpaid bills.

However, Oettinger was quoted Saturday as saying: "We agree that the gas sector should not be a priority in possible economic sanctions — whether on the European or Russian side."

He says he's "against reducing or even breaking off gas relations with Russia in the coming years. However, we must pursue our diversification strategy."