China said it is “strongly dissatisfied” with the US’s decision to complain to the World Trade Organization about Beijing’s protection of intellectual property rights, as trade tensions between the two countries step up a notch.

In a statement posted on China’s Ministry of Commerce website, Wang Xinpei, a ministry spokesman, said the Chinese government greatly regrets the US’s planned move, which “goes against the consensus between leaders of both countries to strongly develop bilateral trade relations and to appropriately resolve trade problems.”

The plan “seriously hurts the cooperative relationship developed between both countries in this area and will exert a negative effect on bilateral trade,” said Wang.

Separately, the official Xinhua News Agency cited State Intellectual Property Office Commissioner Tian Lipu as saying the US decision is “not a sensible move.”

The comments come after US Trade Representative Susan Schwab said Monday the US will file twin cases to the WTO challenging China’s lax enforcement of copyright violations as well as restrictions on the distribution of foreign movies, music and printed materials.

“Piracy and counterfeiting levels in China remain unacceptably high,” she said.

Trade frictions between the two countries have been growing, with the US’s latest claims coming on the heels of Washington imposing last month preliminary tariffs on imports of Chinese sheet paper ranging from 10.9% to 20.4%, and a WTO case filed by the US in February in which it alleged Beijing had given unfair subsidies to a range of Chinese industries.

The trade disputes will also cast a shadow over a high-level visit by Chinese Vice Premier Wu Yi to the US in May as part of a strategic economic dialogue between the two countries. A person familiar with situation said last week that China is drafting plans to buy US$12.5 billion of US goods ahead of that visit.

In the past few years, China has been seeking to improve its protection of intellectual property rights, as government officials increasingly recognize that such protection is necessary if the country is to develop its own technologies and brands. But counterfeits of western media and fashion goods remain widely available in Chinese cities.

China’s judiciary will punish people who make or sell at least 500 pirated discs storing movies, music or software, with prison sentences of up to 3 years, Xinhua cited Tian as saying. The previous threshold was 1,000 discs.

“The United States has filed a WTO complaint right when China is forging ahead with its IPR protection efforts,” Tian was quoted as saying in the Xinhua report.

Premier Wen Jiabao also addressed the issue in his annual report to the National People’s Congress, China’s legislature, held in March.

“We will move quickly to formulate and implement a national strategy for intellectual property rights to strengthen protection of them,” he said.

As part of its efforts to curb piracy, China last year started requiring computer manufacturers to ship their products loaded with legitimate copies of operating-system software.

Schwab acknowledged China’s leaders have made progress in improving property rights protection for movies, music, books and other goods, but said the US and China haven’t been able to agree on legal changes the US believes are needed for China to comply with its WTO commitments.

Wang of the Chinese commerce ministry said: “The Chinese government has always taken a resolute attitude to protecting intellectual property rights, with results that are evident to all.”

Wang added China hasn’t yet received the WTO’s request for consultation over the US complaints, and will “seriously study” and “vigorously deal” with the request once the US formally raises it.

The trade actions come as China’s huge trade surpluses are exacerbating some US politicians’ impatience with Treasury Secretary Henry Paulson’s approach of stressing engagement and dialogue with China to deal with bilateral trade problems.

China said its trade surplus in Mar