China and the G77 claimed that the Copenhagen Climate talks have broken down, degenerating into a fight between developed and the developing world.

The chief negotiator for China and the G77, Mr. Di-Aping said 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.

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.

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.

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 industrialized nations of going back on their commitment to fight climate change.