Xie Zhenhua, Chinese special representative on climate change issues delivers a speech during the China-U.S. Climate Leaders Summit in Los Angeles, the United States, on Sept. 15, 2015. [Photo/Xinhua]

The Climate Leaders Declaration and a series agreements were signed Tuesday by U.S. governors and mayor with their Chinese counterparts who attended the China-U.S. Climate Leaders Summit in Los Angeles.

The two-day meeting, with a full name of "China-U.S. Climate-Smart/Low Carbon Cities Summit," was the first of its kind at the provincial and city level between the two countries.

It fulfills a key element of the China-U.S. Joint Announcement on Climate Change by Chinese President Xi Jinping and U.S. Presidents Barack Obama last November, which has a part to implement the climate goal of each country at local government level.

The Summit "shows the determination of both countries to continually deepen and strengthen cooperation on climate change, and to engage city, state, municipal, private-sector, and NGO partners in this critical effort," the White House said.

Yang Jiechi, the Special Envoy of President Xi and U.S. Vice President Joe Biden will attend the closing ceremony Wednesday.

Chinese cities and provinces Beijing, Shenzhen, Wuhan, Guangzhou, Sichuan, Hainan, Guiyang, Zhenjiang, Jinchang, Yanan and Jilin, and U.S. states and cities including California, Connecticut, Los Angeles, Atlanta, Boston, Portland, Seattle, Houston, Salt Lake City, Des Moines, Carmel signed the Declaration and other working agreenments, such as the California-China Urban Climate Collaborative (CCUCC) and the Memorandum of Understanding between the cities of Shenzhen and Los Angeles and similar agreements between other cities.

As the world's largest developed and developing nations, the U.S. and China represent about 40 percent of the world's carbon emission, California Govenor Jerry Brown said, and as most of the population are in cities, the actions of cities are very important.

"The summit provides an opportunity for local leaders to exchange their experience of practice and learn from each other," Xie Zhenhua, Chinese special representative on climate change issues, said at a press conference after the opening ceremony.

"I heard that about a dozen of Chinese cities are commited to reach the peak years for carbon dioxide emissions earlier than the national goal by around 2030. It is very impressive, " Todd D. Stern, the Special Envoy for Climate Change at the U.S. State Department, said in his speech at the summit.

China announced to cut carbon dioxide emissions per unit of gross domestic product (GDP) by 60 to 65 percent from the 2005 level by 2030 in its "Intended Nationally Determined Contributions,"submitted earlier this year to the Secretariat of the UN Framework Convention on Climate Change.

Some U.S. state and city governments also set ambitious carbon-reduction targets.

California announced to reduce emissions by 80 to 90 percent below 1990 levels by 2050. Los Angeles has a goal of cutting emissions to 45 percent below 1990 levels by 2025, 60 percent below 1990 levels by 2035 and 80 percent below 1990 levels by 2050, and the City of Seattle is committed to become carbon-neutral by 2050.

"Cities lead, mayors lead. When we do something, things will be changed," said Houston Mayor Annise Parker.

Several forums and roundtable talks will be held during the two-day summit, discussing city carbon reduction, renewable energy, environmental friendly business and other related topics.

The second China-U.S. Climate Leaders Summit will be held in Beijing next year, Xie said.