The Czech Republic, which holds the rotating European Union (EU) Presidency, and the European Commission on Thursday expressed concern over the gas dispute between Russia and Ukraine and asked for continued negotiations to find a solution.
"All existing commitments to supply and transit (gas to the EU) must be honoured," Czech Deputy Prime Minister Alexandr Vondra was quoted as saying in a joint statement of the two EU institutions.
EU Energy Commissioner Andris Piebalgs said the situation at the EU border would be monitored closely.
"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," said the Commissioner.
Russia's natural gas monopoly Gazprom cut off all gas supplies to Ukraine after talks on Ukraine's debts and a new contract for 2009 supplies failed on Wednesday.
Both Moscow and Kiev have assured that supplies to the EU via Ukraine would not be disrupted.
A quarter of the EU's gas needs comes from Russia, 80 per cent of which is transited through pipelines that run across Ukraine.