However, Russia denied it was responsible for the cut in supply and accused Ukraine of blocking the transit of gas to southern and eastern Europe.

Alexei Fyodorov, a Gazprom official in Sudzha on the Russian-Ukrainian border, said: "Gas has stopped flowing in Ukrainian territory because Ukraine did not organise further transit of gas to European consumers.

"I stress Gazprom has not cut off gas to European consumers along this gas line."

In turn, Kiev said Gazprom was to blame for the block in supply because it had imposed "unacceptable" conditions for its transit through Ukraine.

EU deal

Earlier on Tuesday, Russia had resumed supplies to Europe via Ukraine after agreeing to an EU-brokered deal.

Gazprom said it had sent its first 76 million cubic metres of gas at 10am (0700 GMT).

The agreement appeared to falter almost immediately, with Ukraine seeking to involve the EU in its dispute with Russia over payments owed to Moscow and future tariffs for fuel supply.

Yury Prodan, the Ukrainian energy minister, called for Europe's backing in the pricing dispute that had prompted Russia to stop supplies on January 1.

"The European community is interested and will participate in our negotiations with Russia," Prodan said during a televised parliamentary debate.

However, a source in Brussels told the news agency AFP that the EU was "very sceptical" about getting involved.

Fifteen states cut-off

Earlier on Tuesday, Jose Manuel Barroso, the head of the European Commission, telephoned Vladimir Putin, the Russian prime minister, to express the EU's "disappointment" at the weak flow of gas via Ukraine to Europe.

Barroso also voiced concerns that monitors deployed to oversee the supply of gas to Europe face "difficulties" in carrying out their work in both Russia and Ukraine.

Experts say it could take between 24 and 36 hours for the gas pumped via Ukraine to reach Europe, where 15 countries have been left without heating since exports were cut off last Wednesday.

Russia cut off all shipments to Ukraine after the two countries failed to renew an agreement for 2009 and Moscow accused Kiev of stealing gas destined for its European clients.

Ukraine, an ex-Soviet state with pro-Western leaders, has also angered the Kremlin in recent months because of its attempts to join Nato.

The dispute has damaged the reputation of both countries as reliable energy partners with Europe once again seeking out alternative energy sources and routes.

The EU relies on Russia for about one quarter of all the natural gas it needs, and 80 per cent of that arrives via pipelines crossing Ukraine.