"I don't believe having discussion or not having discussion of the Iran nuclear issue is the determinant of the relevance of this conference," foreign ministry spokesman Liu Jianchao told a briefing in Shanghai.

Ahmadinejad is only a guest at Thursday's summit of the Shanghai Cooperation Organization, which groups China, Russia, and four Central Asian states. Iran is an observer nation along with Pakistan, India and Mongolia.

Russian President Vladimir Putin, Pakistan's Pervez Musharraf and the leaders of Kazakhstan, Kyrgyzstan and Tajikistan and Uzbekistan were all in town for the meeting.

But attention was expected to be on Ahmadinejad more than anyone else, with the hardline Iranian leader slated to hold his first meeting with Chinese President Hu Jintao on Friday following the summit.

Ahmadinejad was also set to meet Russian President Vladimir Putin for the first time since an encounter at the United Nations last year.

His meetings with Hu and Putin come at a crucial time in the global standoff over Iran's nuclear program, with Tehran considering a new international offer of incentives in exchange for it halting uranium enrichment.

Even so, it was unclear what might actually be achieved by the Shanghai talks in regards to Iran's nuclear program, argued David Zweig, a China expert at Hong Kong's University of Science and Technology.

"It's good to have the two leaders, Hu Jintao and Vladimir Putin, sit down with Ahmadinejad and perhaps help him understand the need not to go down the nuclear road," Zweig said.

"The soft line on these issues has tended not to work. Look at North Korea, where China has a lot more influence than it has with Iran. In general, if states decide to build the bomb, they do it."

China has hosted a series of six-nation talks in a bid to persuade North Korea to abandon its nuclear ambitions, so far making extremely limited progress.

The participation of Iran at the Shanghai summit has already drawn fire from the United States, which remains wary about China and Russia's cosy relationship with Tehran.

China and Russia have significant business interests in Iran, with energy-hungry Beijing in negotiations for a slice of its oil reserves, the world's fourth largest.

"It strikes me as strange that one would want to bring into an organization that says it's against terrorism... one of the leading terrorist nations in the world -- Iran," US Defense Secretary Donald Rumsfeld said this month.

Although Washington accuses Tehran of sponsoring terrorism, Beijing and Moscow disagree.

Ji Kaiyun, an expert on Sino-Iran ties at Southwest University in China's Chongqing city, said Beijing had made it clear it did not want to be seen as a threat to the United States.

"China will not challenge, and China does not aim to transform, the US-led international order. Sino-American ties take precedence over Sino-Iranian ties. China will not clash with the United States over Iran," Ji said.

But others say China's willingness to talk with Tehran may be sending a signal to Washington about how to best handle the issue.

"The Americans have a bad record for having very little to show for ostracising states -- Cuba, North Korea and Iran," said Paul Harris, a US foreign policy expert at Hong Kong's Lingnan University.

"Naturally, the Chinese way is to take a different approach -- they don't care who they talk to and by letting the Iranians on board... it sends a signal to the United States that says your way is not the only way."

Related Links
-