Chinese President Xi Jinping addresses the United Nations Sustainable Development Summit 2015 at the UN headquarters in New York, Sept 26, 2015. [Photo/Xinhua]

Chinese President Xi Jinping on Saturday pledged a US$2 billion fund to facilitate developing countries' implementation of the post-2015 development agenda as part of Beijing's efforts to play a greater role in fighting global poverty.

The figure is an initial pledge of the South-South cooperation assistance fund, Xi told the United Nations' Sustainable Development Summit at UN headquarters on Saturday, adding that China will increase investment in poor countries.

In his first-ever UN address, Xi also said China would act "by putting justice before interests and joining other countries in a concerted effort to realize the post-2015 agenda".

Xi said that China also would step up investment in least-developed countries by at least $12 billion by 2030.

He also told the audience that China would relieve debts owed by least-developed countries this year, with elaboration on how much the debts are and which countries owe them.

Other measures also include establishing an international development knowledge center to facilitate studies and exchanges by countries on theories and practices of development, and mulling the establishment of a "global energy Internet" to facilitate efforts to meet the global power demand with clean and green alternatives.

The announcements won applause at the UN.

The Sustainable Development Summit runs from Friday to Sunday ahead of the annual General Assembly gathering of world leaders that begins on Monday. More than 150 heads of state and government attend the summit, which aims at formally adopting the 2030 Agenda for Sustainable Development to guide the development of the international community over the next 15 years.

A new global agenda to end poverty by 2030 and pursue a sustainable future was unanimously adopted on Saturday by the 193 UN member states.

The global body says the effort could require up to US$5 trillion a year.

Tegegnework Gettu, undersecretary-general for the General Assembly and Conference Management, said China has contributed to the UN's Millennium Development Goals, and China's good relationship with the G77 group of developing countries and role in South-South Cooperation have led to developing countries being better engaged at the UN.

"I know China has contributed bilaterally, which is very helpful for the UN, and that China also has increased its multilateral role," he said.

Gettu, whose office is in charge of the General Assembly and conferences, said it has been a while since a head of state from China has addressed the UN. "We are very happy to have him (Xi) here, and it is a very important time to listen to him,'' he said.

Gettu said that China's participation at the UN, where it is one of the five permanent members of the Security Council, has increased and that it has a significant role to play as the world's second-largest economy and one of its most powerful nations.

"Everybody expects China to play an increasing and proactive role at the United Nations, particularly in conflict resolution, in peacekeeping and in development," he added.

Along with working with the UN, Gettu said, "We would like China to continue its efforts in engaging these developing countries."

On the sidelines of the summit, Xi is to chair the Global Leaders' Meeting on Gender Equality and Women's Empowerment, and chair the High-level Roundtable on South-South Cooperation co-hosted by China and the UN.