The EU is demanding the immediate restoration of full gas supplies from Russia as shortages begin to hit several European countries.

Greece, Bulgaria, Romania, Hungary, Poland and the Czech Republic have reported a significant shortage of supplies following a Russian decision to suspend the flow of gas to Ukraine.

Russia had promised maintain supplies to the rest of Europe, but the EU says both sides are failing to honour assurances that they will not allow the dispute to spill over into other countries.

Russia has cut off gas to Ukraine due to the latter's refusal to pay higher prices demanded by Gazprom, the Russian state gas firm.

Moscow has accused Ukraine of siphoning off supplies destined for the EU to make up for the Gazprom decision, but Ukraine denies the accusation.

The EU relies on Russia for around 25% of its gas supplies, with the majority being piped through Ukraine.