BEIJING (AFP) - The fraught climate change talks in Copenhagen have shown that the concept of a "G2" that would see China and the United States ruling global affairs is far from reality, analysts said.

The accord reached last week in Denmark after marathon negotiations has been widely criticised as a failure, and much of that ire has been directed at China and the United States, the world's two largest carbon polluters.

The global powers sparred often at the talks, failing to agree on several key issues, including that of how to verify that emerging economies such as China fulfil their pledges to crack down on greenhouse gas emissions.

"If there is proof times four that there is no G2, it's the Copenhagen conference," said Jean-Pierre Cabestan, professor of political science at Hong Kong Baptist University.

"Nothing can be done without the others."

Shi Yinhong, a political expert at Renmin University, agreed.

"I think that on the one hand, China's position and importance have increased much more, and consultation between the US and China was quite important," said Shi.

"But on the other hand, if you talk about G2 in Copenhagen, you can see G2 confrontation on some very important issues, so I don't think that the G2 is a correct concept."

The idea of a special US-China relationship, dubbed the G2, has been floated in American academic circles since 2006.

It was raised again in January by former US national security adviser Zbigniew Brzezinski in Beijing as the world's largest and third-largest economies celebrated 30 years of diplomatic ties.

The concept again attracted interest following the G20 meeting in April in London, where US President Barack Obama and China's Hu Jintao launched an annual strategic dialogue and agreed to "strengthen ties at all levels."

But experts said the Copenhagen talks had highlighted the fact that the two sides remain far apart on a number of issues.

Russell Leigh Moses, a Beijing-based analyst, said the verification of emissions cuts in particular had displayed a key sticking point in relations between Beijing and Washington.

"There's still anxiety that the United States is out to contain China," he said.

"It also has to do with domestic consequences -- how do you tell local governments that not only are you going to be overseen by Beijing in terms of economic growth... but you're also going to be overseen by other countries?"

Beyond that, the Copenhagen summit also illustrated that China was still trying to work out what role it wanted to play in the world, Moses said.

"Do you want to be a G2, a G8, do you want to be the only superpower in the world?" he said.

For Shi, the conflicts seen at Copenhagen between the United States and China signalled the beginning of a difficult period for relations between the two nations.

"If we consider the Sino-American conflicts in Copenhagen, the potential new arms sales to Taiwan and Obama's potential meeting with the Dalai Lama, relations will have more difficulties in the next few months," he said.

The United States could reportedly soon sell a new batch of arms to Taiwan -- a move that would anger China, which considers the island nation part of its territory.

White House aides have also said that Obama would meet with Tibet's exiled spiritual leader the Dalai Lama "at an appropriate time" after the US leader's November visit to China -- another move which would raise hackles in Beijing.

Commercial ties between the world's largest and third largest economies have been frayed in recent months, with the capitals trading accusations of unfair trade practices.

Another potential irritant could be the trial this week of leading Chinese dissident Liu Xiaobo on subversion charges -- the United States has already urged Beijing to free Liu and end the harassment of political prisoners.

"Relations (between the United States and China) will remain difficult," said Cabestan.

"This shows that Obama's visit to China was a bit of a waste of time -- it was a formality but actually masked important differences."