SINGAPORE — China's dependence on increasing amounts of oil imported from potentially unstable areas of the Middle East and Africa through vulnerable shipping channels has become an uncomfortable fact of life for the government in Beijing.

Chinese policymakers have called it their "Malacca dilemma," a reference to fears that the Straits of Malacca and Singapore in Southeast Asia, the channel used by most ships steaming between East Asia and the Middle East-Africa region, could be disrupted or even closed in a crisis.

Countries flanking the straits, chiefly Indonesia, Malaysia and Singapore, have sought to reassure China that this key artery for international shipping is secure.