China on Tuesday urged the United States to revoke unilateral tariffs imposed under the International Emergency Economic Powers Act.

In a statement, China’s Commerce Ministry said Beijing had always opposed all forms of unilateral tariff increases, adding that “there are no winners in a trade war, and protectionism leads to a dead end.”

The ministry said it was conducting a comprehensive assessment of the content and impact of a U.S. Supreme Court ruling related to the tariffs imposed by Washington.

It added that the unilateral measures by the United States “not only violate international economic and trade rules, but also contravene U.S. domestic law and do not serve the interests of any party.”

There was no immediate comment from the White House.