WASHINGTON - Vice-President Xi Jinping called on the United States to adjust its economic policies and end restrictions on high-tech exports to China, which he said would help level out the trade imbalance between the two nations.

In a luncheon speech on Wednesday, Xi said China's trade surplus dropped from more than 7 percent of GDP to 2 percent of GDP last year, placing it within a normal range by international standards.

"The reform of the renminbi exchange rate formation mechanism has played an important role in this process," Xi said.

"It is very important when addressing the China-US trade imbalance that the United States adjusts its economic policies and structure, including removing various restrictions on exports to China, in particular, (and) easing controls on civilian high-tech exports to China as soon as possible," Xi said.

"This will help balance China-US trade, stimulate economic growth and job creation in the United States, and improve the balance of US international payments."

According to Chinese official figures, US exports to China reached $122.2 billion in 2011, up 20 percent from the previous year, while American imports from China jumped to $324.5 billion, an increase of 15 percent.

Xi said China has proposed to the United States a framework for promoting two-way trade and investment.

"Our two sides need to continue to work together to get over difficulties, advance our business cooperation to a higher level and explore new areas, and create new highlights of mutually beneficial cooperation," Xi said.

US Secretary of Commerce John Bryson said Xi's US visit is "an important and timely step", and the vice-president has made a strong commitment to healthy China-US relations.

- Wu Jiao and Chen Jia