In Beijing, the Chinese government defended its imports of oil from Iran as completely fair and reasonable.

The Foreign Ministry's remarks came after new customs figures showed imports of oil from Iran in May rose by 39 percent over April, in spite of American demands that they be reduced.

China's imports of crude from Iran fell by nearly 25 percent in the January to May period because of a commercial dispute between the Chinese oil major UNIPEC and its counterpart, the National Iranian Oil Company. Following a resolution, however, May's rebound means Iran is once again China's third largest supplier, after Saudi Arabia and Angola.

America and its Western European allies are now trying to organize an international embargo on Iran's oil in order to force the Islamic Republic into complying with demands concerning its nuclear program.

The Western powers accuse Iran of secretly developing nuclear weapons. Iran rejects the accusation, saying its program is for civilian purposes only.

China is the only major buyer of Iranian oil that has not yet been granted exemption from sanctions America is threatening to impose on countries that do not cut their purchases of Iranian oil. Ahead of a deadline for compliance set for this Thursday, last week US Secretary of State Hillary Clinton said she believed China was slowly but surely taking action.

Chinese experts, however, say Clinton was likely mistaken.

Beyond energy security, analysts say China also has suspicions that America's real aim in pressuring Iran is to strengthen its hegemony over the Middle East. At the annual summit of the Shanghai Cooperation Organization in Beijing earlier this month, a declaration by China, Russia and four Central Asia Nations voiced deep concern over the Iranian situation, opposed the West's sanctions and said any attempt to settle the issue through the use of military force was unacceptable.