The White House is reconsidering the trade barriers it has put up before exports of advanced technology to China, a US official said on Wednesday.

"As you know, we are reviewing our high-technology export regulations," said John Holdren, US assistant to the president for science and technology.

"Certainly, I hope some of those changes will address some of the concerns that our colleagues in China have had, but this is a complicated domain. Where the technologies are judged to be relevant to national defense, those prescriptions will continue. But we hope that in other domains, there will be changes that will benefit China."

Earlier reports said that China has called for the US to ease the restrictions it has placed on exports of high-tech products. That will help to meet the increasing Chinese demand for technology related to clean energy and environmental protection.

But, despite China's willingness to buy such products from the US, the US has not changed its export regulations.

According to media reports, 16.67 percent of China's imports from the US were composed of high-tech products in 2001. By last year, the number had fallen to 6.26 percent, a result of tightened US export restrictions.

In late March, Gary Locke, US ambassador to China, said at a news conference that the US was planning to lift a ban imposed on exports of 46 high-tech products to China. Even so, a Ministry of Commerce spokesman said on April 17 that the ministry had not seen any steps taken toward that end.

Holdren spoke to China Daily at a conference that last from Tuesday to Wednesday in Beijing, where China and US science and technology officials discussed the possibility of cooperating on projects related to environmental protection, clean energy, agriculture technology, health and similar matters.

At the conference, China's Ministry of Science and Technology signed a project protocol with the US Department of Agriculture and a memorandum of understanding with the US National Science Foundation.

Meanwhile, Minister of Science and Technology Wan Gang said the Chinese government is doing more to protect intellectual property rights as international cooperation on science and technology becomes more common.

"In 2011, China's number of innovation patents increased by 30 percent, while the value of technology trading increased to 476.4 billion yuan ($75.75 billion), an increase of 33 percent," Wan said.

"With stricter law enforcement, the Chinese government is trying to foster a more open and fair atmosphere for innovation and to promote global cooperation," Wan said.

The talks will be the third round in a series that China and the US have held on similar topics. The first took place in October 2010 and the second in May 2011.

Through the first two rounds, the negotiators agreed to carry out various research projects together, such as building and operating a $150 million China-US Clean Energy Research Center.

"The two countries also signed an agreement to share the intellectual right of innovation at the center," said Cao Jianlin, deputy minister of science and technology.

Besides such cooperation on science and technology projects, science policies is also an important topic in the dialogue, Cao said.

"China did not move away from a planned economy until recent decades, so these enterprises have only a few research departments. That's different from the US," Cao said.

"In order to encourage enterprises to innovate, we should do more to protect intellectual property."