The chief negotiator for China and the small African nations at Copenhagen has accused Prime Minister Kevin Rudd of lying to the Australian people about his position on climate change.

Lumumba Di-Aping, who represents China and the G77 group of small countries, was speaking as the talks remained deadlocked and world leaders, including Mr Rudd, began arriving in the Danish capital.

Mr Di-Aping said he had high expectations of Mr Rudd, but claimed that throughout the negotiations the Australian Government has not matched its actions with its rhetoric.

"The message Kevin Rudd is giving to his people, his citizens, is a fabrication, it's fiction," he said.

"It does not relate to the facts because his actions are climate change scepticism in action.

"All that Australia has done so far is simply not good enough.

"It's puzzling in the sense that here is a Prime Minister who actually won the elections because of his commitment to climate change," he added.

"He was the only Prime Minister who came and clearly said we have to do something, we have to join Kyoto protocol and all the rest.

"And within a very short period of time he changes his mind, changes his position, he starts acting as if he has been converted into climate change scepticism. All what Australia has done so far is simply not good enough.

The G77 and China claim that the talks have broken down, degenerating into a fight between the developed and the developing world.

Mr Di-Aping accused Mr Rudd of trying to gain a strategic economic advantage by siding with the United States and the European Union at Copenhagen.

"Australia is committed to killing Kyoto," he said.

"All the actions of Prime Minister Kevin Rudd is basically a move away and a killing of Kyoto Protocol."

He says the talks have reached a deadlock because the developed world is not committed to helping poor countries in their efforts to adapt to and mitigate the effects of climate change.

Meanwhile, world leaders have begun arriving at the Copenhagen summit as efforts continue to salvage the talks.

Full ministerial sessions have begun, amid fears too little progress has been made so far.

Mr Rudd told a news conference in Copenhagen that his aim at the climate change talks is to get the best possible agreement in Australia's national interest.

He said that meant getting a genuine agreement between rich and poor countries to tackle climate change for the first time in history.

"It also must be an agreement which is the cheapest, the most effective, the most pro-jobs agreement possible," he said.

"Just as the Carbon Pollution Reduction Scheme is the cheapest most effective way to act on climate change locally, so too is an agreement here in Copenhagen the cheapest and most effective way to act globally."

'Come a long way'

UN Secretary General Ban Ki-Moon says rich and poor nations should stop blaming each other for their differences and bring new and more ambitious proposals to the table.

Speaking at the opening of the plenary session, Mr Ban urged the delegates to compromise to overcome problems encountered so far.

"We have come a long way. Let us not falter in the home stretch," he said.

"Our goal is to lay the foundation for a legally binding climate treaty as early as possible in 2010.

"We do not have another year to deliberate - nature does not negotiate with us."

Earlier, a senior UN official warned that negotiations were progressing too slowly and that there was still an enormous amount of work to be done.

Observers say there are still deep divisions between rich and poor nations, which highlighted by the Americans saying they do not expect to offer any further cuts in their carbon emissions.

Developing countries have meanwhile accused industrialised nations of going back on their commitment to fight climate change.

French President Nicolas Sarkozy, US President Barack Obama, German Chancellor Angela Merkel and British Prime Minister Gordon Brown have held a 50-minute joint telephone call to discuss progress at UN climate talks in Denmark.

A French statement says the four leaders covered the main areas that are currently being negotiated at the conference in Copenhagen, but provided no details on their discussions.

In Copenhagen, Governor of California Arnold Schwarzenegger told delegates that leaders and ministers will not be able to find a solution on their own.

"They need to co-operation (sic) the activists, the scientists, the universities," he said.

"They need the individuals whose vision and determination create movements. So ladies and gentlemen, let us regain our momentum, let us regain our purpose, let us regain our hope."