A U.S. diplomat told the World Trade Organization in Geneva Friday that a recent ruling limiting the justification of tariffs on national security grounds was “seriously flawed” and should not be allowed to become the standard internationally. Trump administration has cited national security to justify its tariffs on steel and aluminum imports.

The WTO ruled in April that tariffs based on national security had to involve an “emergency in international relations” relating to “the ‘hard core’ of war or armed conflict,” a standard that would appear to limit them to ongoing armed conflicts. The case involved a challenge by Ukraine to some Russian trade restrictions. The ruling was officially adopted Friday.