The European Union Monday urged Gazprom and Ukraine to resolve a dispute over unpaid gas deliveries after the Russian company cut supplies to the country by 25 percent, according to EU Business.

"The commission has called (on) the two parties to find quickly a definitive solution to this commercial issue," commission spokesman Michele Cercone told journalists in Brussels.

"We continue to monitor closely the development of this situation," he added.

Earlier Monday, Gazprom reduced gas supplies to Ukraine by 25 percent after talks in a pricing dispute failed, echoing a standoff in 2006 when a cut hit the flow of gas to several European countries in the middle of a cold snap.

"Gazprom has assured the commission that gas supplies to the European Union will not be affected," Cercone said.