On his fifth visit to China, aimed at deepening co-operation between the two countries, Mr Chávez also announced that a joint investment fund would be doubled in size to $12bn (€8.2bn, ￡6.5bn).

Mr Chávez, whose anti-US rhetoric has sharpened recently, has long hoped that fast-growing China could become an important alternative market for Venezuelan crude and allow him to divert supplies from the US, which has caused unease in Washington. The Venezuelan leader said exports to China would more than treble to 1m barrels per day by 2012.

Although there remains considerable scepticism within the oil industry about the likelihood of Venezuela selling large volumes of oil to China because of distance and technical obstacles, the visit underlines the two governments' strengthening relationship.