China, now the sole holdout resisting new nuclear sanctions against Iran, will likely approve a weakened UN text if it secures concessions from the West, experts say.

Russian President Dmitry Medvedev this week made his most explicit threat yet to act against Tehran, but the public position of China -- which has longstanding energy interests in Iran -- remains in support of more talks.

Beijing has a long history of opposing sanctions, but a UN Security Council resolution with little bite would allow it to save face with the United States and Europe, both key trading partners, observers say.

"China is preparing the ground to effectively water down the expectations and the impact of any sanctions that might eventually be agreed," said Sarah Raine, a China expert at Britain's International Institute for Strategic Studies.

"The question is making sure from China's perspective that those sanctions have minimal impact on its interests there."

Despite Medvedev's remarks in Paris, Chinese foreign ministry spokesman Qin Gang reiterated Tuesday that there was "still room for diplomatic efforts" -- language Beijing has used consistently for months.

China has supported anti-Iran sanctions at the last minute three times before -- but only after they were diluted to protect its interests.

"Previously, both Russia and China have been able to secure quid pro quos from the West, from Europe and the United States in order to be tougher on Iran," said Samuel Ciszuk, an energy analyst for IHS Global Insight.

"Russia is not really in that position lately... the Chinese obviously are."

The United States and Israel have been ratcheting up the pressure on Beijing to come on board for more sanctions, with both countries sending high-level officials to the Chinese capital in recent days.

But China wields an all-important veto on the UN Security Council. As such, it could potentially scupper any sanctions resolution -- and it is warming up to its new-found bargaining power.

It could well seek a more conciliatory approach from the United States, which has angered Beijing by selling arms to Taiwan and by receiving the Dalai Lama, as well as by imposing anti-dumping duties on Chinese goods.

"China's not comfortable in the (UN) spotlight but it's not as uncomfortable as Washington had clearly hoped," Raine said.

The five permanent Council members -- Britain, China, France, Russia and the United States -- plus Germany have been involved in protracted talks with Iran on its suspect atomic programme, which the West says is a covert weapons drive.

US Secretary of State Hillary Clinton last week called for a new resolution within the "next 30 to 60 days" but backed away from that timetable on Monday, saying it could take months -- suggesting China may be digging in its heels.

"In China's mind there cannot be really far-reaching sanctions," said Willem van Kemenade, the Beijing-based author of the recent book "Iran's Relations with China and the West".

"It doesn't work because the Chinese are far more circumspect" on whether Iran is truly pursuing a weapons programme, he added.

The Iran standoff highlights how China's thirst for oil to fuel its booming economy has influenced its foreign policy over the past decade, Ciszuk said.

However, Zhu Weilie, head of the Middle East Studies Institute at Shanghai International Studies University, said Iran's trade influence with China was far outweighed by its commercial ties to the West.

"The US certainly matters most to China in terms of interests," he said. "China has extremely big trade volumes with the US, Europe and Japan, while trading volumes between China and Iran are just 20 billion dollars a year."

For van Kemenade, Beijing's position on Iran is ultimately about more than just protecting its interests or winning concessions.

"It also wants to prevent the US and, secondly Europe, from behaving like hegemons dictating to non-Western countries how to behave," he said.

"That is a core principle of Chinese policy -- anti-hegemony and no sanctions. It has been a victim of sanctions itself for so long. There is an aspect of common victimhood that is very important here."