The tit-for-tat has analysts fearing a protracted and escalating trade war, since President Donald Trump has threatened to enact other tariffs on hundreds of billions of dollars in Chinese goods.

China’s Ministry of Commerce called the U.S.’ move illegal.

“The United States violated the WTO (World Trade Organization) rules and launched the largest trade war in economic history to date,” the ministry said in a statement. “This kind of taxation is a typical trade bullyingism, which is seriously jeopardizing the global industrial chain and value chain security, hindering the pace of global economic recovery, triggering global market turmoil, and will affect more innocent multinational corporations, general enterprises and ordinary countries. Consumers will not only be helpless, but will also harm the interests of American businesses and people.”

Many of China’s retaliatory tariffs are aimed at America’s agriculture industry, affecting soybeans, corn, tobacco and cashews, among other products. China is a top consumer of U.S.-grown soybeans.

The U.S. tariffs target pharmaceuticals and construction goods, including parts for air conditioners, compressors, furnaces and ventilation equipment.

The trade skirmish started in March, when the White House announced it was enacting a 25 percent tax on imported steel and a 10 percent duty on aluminum in an effort to counteract unfair trade practices from China and other most countries.

After temporarily exempting allies Canada, Mexico and the European Union from the metals tariffs, the duties were extended to imports from those countries. All have responded with their own levies on popular U.S. products such as syrup and bourbon.  

Trump is confident the U.S. economy can weather the effects of a prolonged trade fight. In a March post on Twitter, the president said trade wars are “easy to win.”