China and the United States Thursday pledged to deepen clean energy cooperation as U.S. commerce chief led a large green power delegation to Beijing.

"As major energy producers and consumers, China and the United States can work together extensively in the clean energy field," Chinese Vice Premier Li Keqiang told U.S. Commerce Secretary Gary Locke in Beijing.

The driving force behind cooperation, Li said, lies in the fact that China is actively pushing ahead with clean energy projects while the United States has green energy expertise and technology.

Li encouraged the two countries to work more closely in clean energy,greenhouse gas emissions reduction, technological development to add to the momentum of sustainable development.

Locke is leading a delegation of business executives from American clean energy companies eyeing China's fast growing green energy market, the size of which the United States has predicted will be 100 billion U.S. dollars by 2020.

"These 24 companies we brought from America represent a cross-section, a variety of different sectors," Locke said at the start of the meeting.

"But they still represent the best the United States has to offer in terms of clean energy, energy efficiency, electricity generation and distribution," said Locke, who earlier travelled to Hong Kong and Shanghai on the trade mission that started Monday.

The diverse trade mission, the first one led by a U.S. cabinet-level official since Barack Obama assumed the presidency, includes leading energy firms like General Electric and First Solar as well as less well-known companies.

Locke, on his third visit to China since he became U.S. commerce chief, characterized clean energy as "an extremely promising industry to foster areas of growth and create new jobs."

He underscored the U.S.'s commitment to working closely with China in clean energy.

Locke will join U.S. Secretary of State Hillary Clinton, U.S. Treasury Secretary Timothy Geithner and other cabinet officials for the Second China-U.S. Strategic and Economic Dialogue scheduled for Monday and Tuesday in Beijing.