"Without prior warning and in clear contradiction with the reassurances given by the highest Russian and Ukrainian authorities to the European Union, gas supplies to some EU member States have been substantially cut. This is completely unacceptable", an official release of the European Union reads.

"The Czech EU Presidency and the European Commission demand that gas supplies be immediately restored to the EU and that the two parties resume at once negotiations ", EU officials stated.

Romanian Prime Minister Emil Boc informed the EU Energy Commissioner, Andris Piebalgs, on the gas delivery halting at the Isaccea 2 Transgaz entry point, a Romanian Government release informs.

EC president Jose Manuel Barroso and the Energy Commissioner are expected to involve in order to find a solution for the situation.