A host of Chinese companies, including high-profile Chinese telecom equipment maker Huawei, suffered setbacks to their overseas acquisition and merger plans because of US national security fears.

Wang Zhile, a professor at the Chinese Academy of International Trade and Economic Cooperation, said the definition of so-called national security is ambiguous and convenient for protectionism.

Both the US and China should abandon any "Cold-War mentality", as the two countries can benefit from increased trade, he said.

China is determined to continue opening up because competition is the best way to push reform forward and improve people's livelihood, Commerce Minister Chen Deming said last Saturday.

China has plans to further loosen restrictions on foreign investment but developed countries also need to provide equal market access, Chen said.

In 2010, China's overseas direct investment was $59 billion, equal to only 60 percent of foreign direct investment in China, according to the Ministry of Commerce.

Meanwhile, trade experts urged the US to further reduce trade imbalances between the two countries by lifting controls on imports of high-tech products.

"The invisible loss caused by restrictions the US levied on high-tech imports to China is hard to estimate," said Long, but it's clear that the US has lost a number of business opportunities to its rivals.

China's robust demand for imported high-tech products continue to grow while imports from the US continue to shrink, so more orders were won by European and Japanese companies, he said.

"It's a great pity for US companies," Long said.

In the first three months, the inflow of foreign direct investment in China surged by 29.4 percent from a year earlier to $30.34 billion, according to the Ministry of Commerce.