Iran said that it was considering cutting oil sales to six EU countries but would not do so "at the moment". Unperturbed European officials said they were looking for other suppliers in any event.

State broadcaster IRIB reported on its website that the ambassadors of France, Greece, Italy, the Netherlands, Portugal and Spain were called to the foreign ministry in Teheran and warned that "Iran will revise its oil sales to these countries".

The warning was in retaliation to an EU ban on Iranian oil imports that is being phased in as contracts expire up to July 1.

But after world oil prices spiked - in part because Iran's English-language Press TV had reported Iran had already "cut" oil exports to those countries - the media reported that no steps had yet been taken to reduce oil exports to the EU.

"Due to humanitarian reasons and the cold weather on the continent, Iran will not do so at the moment," broadcaster al-Alam said.

"We came to a conclusion to send a strong and serious message to the Europeans about our oil contracts," IRIB quoted a foreign ministry official, Hassan Tajik, as saying.

"Our message is that we can immediately replace our oil customers," he said.

A diplomat from one of the EU embassies involved in the discussions with the Iranian foreign ministry said his ambassador had not received notification of a cut in Iranian oil sales.

The European Commission said that, even if Iran did cut sales to the EU, it would make little difference as buyers were already switching suppliers.

"Oil is something you can get on the international markets, and Saudi Arabia said it would increase its production," said Marlene Holzner, spokesman for EU energy commissioner Guenther Oettinger.

Iran has reacted furiously to Saudi Arabia's promise to pump more oil to compensate for any loss to the market from curbed Iranian exports.

Teheran said such a move would be viewed as "unfriendly".

Iran is the second-biggest producer in the Organisation of Petroleum Exporting Countries, behind Saudi Arabia.

It pumps about 3.5million barrels a day, of which 2.5million are exported.

The EU imported about 600000 barrels of Iranian oil a day in the first 10 months of last year, mainly for Italy, Spain and the battered Greek economy.