Unilateralism shown by some countries has posed an "unprecedented challenge" to global trade, a Chinese commerce official said Thursday.

A multilateral trade mechanism is the "fundamental guarantee" of global economic prosperity, Gao Feng, spokesperson for the Ministry of Commerce, said when answering a question about U.S. attitudes towards trade with China at a press conference.

As the world's largest developing country, China has been actively integrating into the world economy and firmly defending the trade system since joining the World Trade Organization (WTO) in 2001, Gao said.

His remarks came amid increasing signs of protectionist and unilateral practices around the globe, including a U.S. investigation into intellectual property protection in China under a rarely used trade law.

"Many WTO members have expressed their concerns about unilateralism," Gao said.

He added that China is open to foreign investment and welcomes overseas companies to set up joint ventures in the country to achieve mutually beneficial development.

China has a favorable investment environment, Gao said, citing complete industrial capacity, skilled workers and a huge market.