“President [Donald] Trump has taken actions on trade in steel and aluminum to protect our national security interests. These actions are wholly legitimate and fully justified, both as a matter of US law and WTO rules,” Lighthizer said in a statement on Tuesday. “By contrast, the European Union has concocted a groundless legal theory to justify immediate tariffs on US exports. Other WTO Members, including China, have adopted a similar approach.

“These retaliatory tariffs underscore the complete hypocrisy that governs so much of the global trading system. For months, the EU, China, and others have criticized the trade policy of the United States, while claiming to champion the WTO. But their recent tariffs prove that they simply ignore WTO rules whenever doing so is convenient,” he added.

Lighthizer is referring to Article XXI of the General Agreement on Tariffs and Trade of the WTO that allows members of the trade organization to protect security interests. The US has imposed 25 percent tariffs on steel and 10 percent on aluminium, claiming security interests. China, Russia, Japan, India, Turkey and the European Union have all said the tariffs cannot be explained by US security concerns and are, in fact, protectionism measures.

“President Trump’s actions regarding steel and aluminum plainly fall within the legitimate scope of Article XXI. Faced with massive excess capacity that puts the very future of our steel and aluminum industries at risk, President Trump took certain measures that he deemed essential to the national security of the United States,” Lighthizer said.

The European Union will levy goods coming from America with tariffs worth €2.8 billion ($3.3 billion) after Washington imposed tariffs on steel and aluminum from Europe. Russia, Turkey, India and other countries will also introduce sanctions against US goods.