BEIJING Iran announced plans on Sunday to build 10 new uranium enrichment plants in a major expansion of its atomic programme, just two days after the U.N. nuclear watchdog rebuked it for carrying out such work in secret.
China and Russia supported the International Atomic Energy Agency's rebuke of Iran for building a uranium enrichment plant in secret, but both countries have long blocked the imposition of stringent economic sanctions on Iran.
He Yafei, a vice Chinese foreign minister, told Reuters last week that China's stance on more sanctions remained the same.
Below are some questions and answers about why China is so ambivalent about international pressure on Iran.
WHY IS CHINA RELUCTANT TO BACK SANCTIONS?
China says it sticks to a doctrine of "non-interference" in the affairs of other nations, partly because it does not want the United States or Europe criticising its behaviour or policies.
It is also wary of signing up to multilateral efforts to pressure individual countries for similar reasons, except in cases such as North Korea which presents a pressing security concern close to home.
WHAT WILL THIS MEAN FOR U.N. EFFORTS TO PRESSURE TEHRAN?
China is a permanent member of the Security Council, so it has a veto on any potential resolution to censure Iran or ratchet up sanctions. While Beijing often abstains from votes on decisions it disapproves of, it is also willing to use its veto.
If Beijing threatens to block a resolution, Western nations that want to increase pressure on Tehran through sanctions or other methods might be forced to act unsupported by the authority of the United Nations.
Alternatively, they would have to wait for something that Beijing considers a more severe provocation.
WHAT TRADE AND BUSINESS TIES DO THE TWO COUNTRIES HAVE?
Growing energy ties bind China, the world's No. 2 crude oil consumer, and Iran, which has the world's second-largest crude oil reserves but desperately needs investment to develop them.
Tehran has turned to Asian firms for energy investment as Western firms succumb to political pressure. Iranian oil made up nearly 12 percent of China's crude imports last year.
Last week, Iranian media reported that China's Sinopec had signed a tentative deal to provide $6.5 billion in financing for oil refinery projects in Iran.
Chinese state companies are also selling gasoline to Iran, which despite its huge crude reserves lacks the refining capacity to meet domestic fuel demand. They stepped into a vacuum left by sellers who halted supplies in anticipation of new sanctions.
Both countries also resent Western criticism of their human rights records, which they condemn as unjustified and politically motivated.
WHY WAS CHINA PREPARED TO BACK SANCTIONS ON NORTH KOREA?
North Korea is on China's border and has hovered at the brink of economic collapse for over a decade. Any disintegration of the regime could spill instability into China.
By contrast, Iran is an important trade partner several thousand kilometres away, with a damaged but functioning economy.
In addition, Pyongyang has twice tested a nuclear device and may have extracted enough plutonium for six to eight bombs.
Tehran says its nuclear programme is for peaceful power generation only. Even if this is not true, Iran's scientists are still several steps away from a potential nuclear weapon.
IS CHINA LIKELY TO STICK TO ITS CURRENT POSITION?
China's leaders will probably bide their time to see how Iran responds to current pressure, whether any further evidence is laid out that would point to nuclear weapons plans, and whether Russia lines up with Western members of the U.N. Security Council. Beijing might ultimately be willing to intervene to prevent Iran developing a nuclear weapon because of fears about a Middle East arms race or worries about global proliferation.
(Reporting by Ben Blanchard; Editing by Bill Tarrant)