European Union governments called on Tuesday for Ukraine and Russian natural gas monopoly Gazprom to clarify their relations after a recent spat over debts cut energy supplies to the former Soviet republics, according to Reuters.

Gas experts from the EU`s 27 nations also said the gas cuts to Ukraine -- which threatened supplies to the EU -- strengthened the case for the bloc to improve coordination of its energy policies.

"The group underlined the importance and the necessity of urgent clarification of relations between Gazprom and Ukraine as far as domestic Ukrainian gas consumption and gas transit towards the EU is concerned," it said.

Ukraine and Russia reached agreement to restore gas supplies to Ukraine last week, averting the risk of cuts in deliveries to western Europe. Moscow had reduced gas supplies to Ukraine, saying it had failed to pay all its debt for past deliveries.

But the two sides still have to work out the difficult details of a scheme organising supplies for the rest of the year, particularly the use of intermediaries.

"The repetition of these incidents has clearly highlighted the necessity of close cooperation between (EU) member states," the EU statement said.

It also noted the need for "effective solidarity" within the bloc, a reflection of concerns especially among eastern European countries that bilateral deals between EU states and Russia could hurt their interests.

Nearly 80 percent of gas imported from Russia by the EU transits via Ukraine and supplies a dozen EU Member States.