US Secretary of State Hillary Clinton said on Thursday the United States would join other rich countries in raising US100 billion annually by 2020 to help developing nations combat climate change.

However, the commitment was conditional on a climate deal being done that committed all major economies to mitigation actions and included demands on transparency.

"In the context of a strong accord in which all major economies stand behind meaningful mitigation actions and provide full transparency as to their implementation, the United States is prepared to work with other countries toward a goal of jointly mobilizing US$100 billion a year by 2020 to address the climate change needs of developing countries," Clinton told a press conference.

She said the funds would come from "a wide variety of sources" -- public and private, bilateral and multilateral, including alternative sources of financing.

The United Nations Framework Convention on Climate Change binds rich nations to quantified emission reductions and provision of financial support to developing nations. The convention does not commit developing nations to emission reduction targets.

China and other developing nations are opposed to demands that their emission control measures be put under international scrutiny to ensure transparency, saying their actions are voluntary.

World leaders continued to arrive in Copenhagen to endorse efforts to reach a deal to curb global warming as the UN climate talks moved into its final summit segment. Clinton said the talks had been "difficult."

(Xinhua News Agency December 18, 2009)