Mexico will start a dispute settlement process at the World Trade Organization over tariffs the Trump administration has imposed on steel and aluminum imports.

The European Union is also seeking WTO involvement against the new measures. The EU submitted a request for consultations with the United States on the steel and aluminum tariffs on Friday. Consultations represent the first step in the WTO dispute settlement process.

Mexico’s economy ministry said in a statement that it believed the US measures, which place 25-percent tariffs on steel and 10-percent tariffs on aluminum imports, violate WTO rules.

“The Mexican government asserts that its actions will continue adhering to the rule of international trade law and will be proportional to the damage that Mexico unfortunately receives,” the statement said.

Mexico already gave notice it would retaliate against the US tariffs by targeting US farm and industrial products, including pork bellies, fruit, and steel. Canada and the EU took similar actions, promulgating new tariffs on a range of US products.

President Donald Trump says the tariffs protect US industry from what he considers to be unfair international competition. The tariffs have also been justified on national security grounds, much to the consternation of the US allies affected by them The tariffs have also complicated the negotiations with Mexico and Canada to revamp the North America Free Trade Agreement.