"During any negotiation, we have many different realities, different interests .. If we only focus on our own interests, we will never succeed," said Achim Steiner, the United Nations Under-Secretary General and Executive Director of United Nations Environment Programme(UNEP), in an interview with Xinhua.

"Climate change is a challenge for humanity. It requires that we look at each other and say how I can help you in order to help me?" he said ahead of the UN climate change conference which is set to begin on Monday.

The Kyoto Protocol, in which the developed nations agreed to limit their greenhouse gas emissions, is due to expire at the end of 2012 and a new agreement will be decided upon in Copenhagen to deal with the issue of climate change.

The United Nations is leading a campaign, Seal the Deal, with an aim to galvanize political will and public support for reaching a comprehensive global climate agreement in Copenhagen.

Steiner said China's recent announcement on greenhouse gas emission reduction target has assisted in triggering fresh momentum in the weeks and days running up to the crucial climate convention meeting.

"It underscores China's determination to continue and to accelerate the decoupling of C02 emissions from economic growth," he said. "And alongside commitments and pledges by other, the United States, the European Union and Japan as well as Brazil, India, Indonesia, Mexico and the Republic of Korea, China's announcement is bringing the opportunity of decisive agreement in the Danish capital this month far closer than perhaps was the case only a few months ago."

Steiner said there is no doubt that industrialized countries should take the better part of responsibility for climate change and the developed countries should provide financial and technological assistance to the developing ones.

"A key issue in Copenhagen is how the international community can support and accelerate this transition to a low carbon, resource efficient Green Economy in developing countries via measures such as technology transfer," he said.

Another test for the Copenhagen conference is whether it can develop a global financial partnership in which developing economies are given sufficient resource to adapt to the climate change already underway while being assisted towards a low carbon path, said the head of UNEP.

"Sums of perhaps 100 billion US dollars a year by 2020 may be needed and there needs to be a quick start fund of several billion dollars almost immediately."

Steiner said while there is a great deal to be done in Copenhagen to realize a decisive and equitable agreement, there is now a real chance that the UN climate convention meeting can be a success.

"Copenhagen could and must be the start of a really new and more creative development path for 6 billion people, rising to 9 billion by 2050," he added.