BEIJING, March 9 (Xinhua) -- China on Friday joined global condemnation of the U.S. decision to impose heavy tariffs on steel and aluminum.

U.S. President Donald Trump formally signed off on 25 percent tariffs on steel imports and 10 percent on aluminum Thursday, with initial exemptions for Canada and Mexico, saying exemptions could be made for other countries through negotiations.

China will defend its rights and interests after assessing any damage caused by the tariffs, Wang Hejun, a Ministry of Commerce official, said on the ministry website.

Calling the move protectionism disguised as national security, Wang urged the United States to respect the multilateral trade system and revoke the policy.

China Iron and Steel Association called on the government to take firm counter-measures on imports from the United States, including stainless steel, galvanized sheets, seamless tube, coal, farm produce and consumer electronics.

The U.S. move not only damages the iron and steel industry across the world, but damages the interests of consumers, especially American consumers, the industry group said on its website.

China Nonferrous Metals Industry Association also issued similar comments, urging the government to take counter-measures on imports of U.S. products ranging from aluminum scrap, coal, farm produce to high-end consumer goods.

Shares of China's steel and aluminum producers tumbled Friday, with Baoshan Iron & Steel Co. down 3 percent to 9.1 yuan (1.4 U.S. dollars) while Liuzhou Iron and Steel Co. fell 2.3 percent to 7.13 yuan.

The broad impact of the tariffs on the Chinese economy will be limited because steel and aluminum account for a small proportion of exports to the United States, and exports have become a less important driver of growth in recent years, with the contribution of net exports to growth falling to 9.1 percent in 2017.

According to Ding Shuang, an economist at Standard Chartered Bank, China's steel and aluminum exports to the United States accounted for less than 0.2 percent of its total exports in 2017 and the impact of the tariffs would be insignificant.

The U.S. administration has made trade deficit reduction a priority, but its protectionist measures have drawn widespread opposition from both U.S. business groups and trade partners.

Last year, China's trade surplus with the United States expanded 13 percent to 1.87 trillion yuan, with exports to the United States up 14.5 percent and imports up 17.3 percent, according to data from China's customs.

Stephen Roach, former chairman of Morgan Stanley Asia and the firm's chief economist, said raising tariffs shows the U.S. administration's fixation on trade imbalances with its partners, including China.

Lacking domestic savings and wanting to consume and grow, America must import surplus savings from abroad while running massive current-account and trade deficits to attract foreign capital, he said in a recent article.

"Going after China, or any other country, without addressing the root cause of low saving is like squeezing one end of a water balloon: the water simply sloshes to the other end," he said.

Ding Shuang projected that "a grand bargain" will be reached between China and the United States with limited damage to bilateral trade.

Trade friction may intensify as Trump seeks trade remedies under the Section 301, raising fears of a widespread trade war, Ding said. However, "this is very likely a tactic of the Trump administration to win the biggest possible concessions."

Ding said China is likely to file World Trade Organization complaints while taking counter-measures against the U.S. farm produces, vehicles and aircraft.