Europe has potential retaliatory measures to U.S. President Donald Trump’s latest threat on steel and aluminum tariffs ready to go, the chair of the European Parliament’s trade committee said on Saturday.

“We have our countermeasures ready for the unjustified tariffs on steel and aluminum. If what has been announced really becomes reality, then we should apply these counter-tariffs immediately,” German MEP Bernd Lange said in a post on X.

Trump announced on Friday a new 50 percent tariff on steel and aluminum would take effect on June 4, up from the previous rate of 25 percent.

“At 50 percent, they can no longer get over the fence,” Trump said during a speech at a U.S. Steel facility in West Mifflin, Pennsylvania.

Trump has been grappling with U.S. courts over his authority to impose tariffs on foreign goods. Two court rulings this week struck down his use of the International Economic Emergency Powers Act to impose reciprocal tariffs on countries around the world as well as duties aimed at China, Canada and Mexico. The tariffs remain in effect after a federal appeals court issued a temporary stay. 

Trump administration officials have promised to use other tools to pursue the tariffs policy while fighting their case on appeal.