China's chief climate official called for the United States, as the world's most developed nation, to do more to tackle climate change.

While the Obama administration has been more active on the issue than previous administrations, it needs to take more steps in taking the lead in cutting emissions, providing financial support and technology transfers, said Xie Zhenhua, vice minister of the National Development and Reform Commission, state-run Xinhua news agency reports.

"We know that there are disputes and difficulties within the United States on legislation, but we hope these, along with the U.S. unwillingness to take more responsibilities, should not be shifted to other countries," Xie said, in remarks to reporters Wednesday.

Xie, head of the Chinese delegation to the United Nations-sponsored Copenhagen climate summit last December, added that China would like to "enhance" cooperation with the United States to deal with climate change.

He said Beijing would issue a report on its emissions-cutting initiatives every two years.

China, the world's largest emitter of greenhouse gases, has pledged to cut carbon intensity 40 to 45 percent below 2005 levels by 2020. Carbon intensity is the amount of carbon released per unit of gross domestic product.

Because China finances its own emissions reduction efforts, unlike developing countries that rely on international financial and technical assistance, it should be exempt from international scrutiny, Xie said. He noted that the issue was a matter of sovereignty.

Xie said he hopes that a follow-up climate summit planned for the end of this year in Cancun, Mexico will be a success.

China also said it would work closely with India in future negotiations on climate change and is interested in increasing cooperation with New Delhi in energy efficiency, renewable energy and forestry.

In related news, the two countries Tuesday formally backed the climate change accord reached in Copenhagen, which calls for limiting global warming to or 3.6 degrees Fahrenheit. They are the last two major economies to sign up.

In a single-sentence letter to the U.N. Framework Convention on Climate Change, the body responsible for international climate negotiations, Su Wei, China's chief climate change negotiator stated that the United Nations "can proceed to include China in the list of parties" signed up under the accord.

Todd Stern, who heads the U.S. climate change negotiating team, told The New York Times he was pleased to see China and India sign on. "The accord is a significant step forward, including important provisions on mitigation, funding, transparency, technology, forests and adaptation," he said.