US President Trump has announced that from June 1st, tariffs of 25% and 10% will be imposed on imports of steel and aluminum from the European Union, Canada and Mexico. The move was immediately condemned by the closest allies in the United States. The United States announced that it would levy taxes on steel imported from the European Union, Mexico and Canada. (The Associated Press) said the move, according to Bloomberg, marked the United States' government's most active trade action against major trading partners in the United States, which have been seeking permanent relief. It is understood that the European Union, Canada and Mexico account for about 40% of the total steel imports in the United States. Among them, October 2017 data show that the largest U.S. ally, Canada exported 5 million 800 thousand tonnes of steel to the United States in the year, ranking the top of the region's exports to the United States. The European Union says it will take immediate measures to retaliate. The Mexico government has vowed to impose tariffs on all products from flat steel to cheese in the United States. The Canadian government announced plans to impose retaliatory tariffs of $16 billion 600 million on US steel, aluminum and other products from July 1st, and the Canadian government will continue to carry out tariffs as long as the US tariffs remain unchanged. "This is a bad day for world trade, and it is completely unacceptable for a country to take unilateral measures in world trade," the president of the European Commission, Jean-Claude Juncker, said in a statement. It is understood that in mid March this year the EU announced a list of tariffs on products, clothing, cosmetics, tobacco and wine, ships, motorcycles, and so on, with a tax rate of up to 25%. As the Trump administration is also considering tariffs on American car imports, it could hit top suppliers from Mexico, Canada, Japan and Germany. In addition, the plan to impose tariffs on China's US $50 billion commodity has exacerbated the market's worries about trade war.