Speaking after an hour-long meeting in the Chancellery in the German capital overnight, Mrs Merkel emerged smiling with Mr Rudd and spoke warmly of an increasingly strong relationship with Australia, even adding that it is "a lot of fun" working with Mr Rudd.

Both leaders spoke of the importance of thrashing out a global goal for limiting climate change but made clear that it would be difficult for the Major Economies Forum (MEF), which is also to meet in L'Aquila in Italy this week, to negotiate a way out of the stalemate before the Copenhagen talks in December.

"We need more work and I warn you at L'Aquila we will not be able to come up with definite figures. We know we need to reduce up to 80 per cent for developing countries - but for emerging countries, we will have to work out the detail," Mrs Merkel said.

"Both Germany and Australia want to see a strong outcome at Copenhagen but we also understand how difficult that is, particularly in the context of the global economic crisis," she said.

The Prime Minister conceded that the world's leaders had "a lot of work" to do before developing nations accepted the notion that "we are all in this together".

"[We have] a lot on our plate to get beyond the point where there is a sense of unease with each other about our respective obligations and we arrive at a point where we can discuss this and what is necessary with our friends from major emerging economies," he said.

"It is highly unlikely that anything will emerge from the MEF in terms of detailed programmatic specificity ... that is what Copenhagen is about. But we as political leaders need to give our negotiators a fresh negotiating mandate, because we are running out of time between now and the end of the year."

Asked about reports that hundreds of people have been killed or wounded during violent protests in the province of Xinjiang, Mr Rudd called on the Chinese Government to show some restraint, although he said he had not had a formal brief on the situation.

He said he had been disturbed by reports of violence, adding that he had never denied that there are continuing human rights problems in China.

Mr Rudd also pledged that continuing requests from the US to accept inmates of the Uighur ethnic group prisoners in Guantanamo Bay would be looked at on their individual merit.