The head of the World Trade Organization has responded to President Donald Trump's threat to leave the institution by warning such a move would cause chaos for U.S. companies operating around the world.

In an Oval Office interview Thursday, Trump warned that he would withdraw from the WTO "if they don't shape up." The president also called the 1990s agreement establishing the body "the single worst trade deal ever made."

Roberto Azevedo, the WTO's director general, said Friday that he was already working with the U.S. and other members to address some common complaints. But he warned that a U.S. exit from the WTO would have chaotic consequences for the global economy and the U.S. itself.