The European Commission and the Czech EU presidency urged Russia and Ukraine Thursday to return to the negotiating table and reach a gas deal so "that gas supplies to the EU are not affected." "All existing commitments to supply and transit must be honoured," Czech Vice-Premier for European Affairs Alexandr Vondra said in a joint statement with the Commission, according to DPA. Russia's gas export monopoly Gazprom said on Thursday it had fully cut gas to Ukrainian consumers in a move that followed a collapse in talks between the two countries on Russian gas supplies to Ukraine. The European Union, whose members are largely dependent on Russian gas supplies, said it will closely monitor the situation at bloc's border. "The EU trusts that we can count upon assurances given that gas supplies to the EU will be unaffected, as a demonstration of the reliability of its gas suppliers," European Commissioner for Energy Andris Piebalgs said in the statement. The EU, however, responded cautiously to Ukraine's call for getting involved in brokering the bilateral gas row. "The Presidency and the Commission are in contact with both sides," the statement said. The Czech Republic assumed the six-month rotating EU presidency on Thursday, taking over from France.