China's economic model represents an "unprecedented" threat to the world trading system that can't be addressed under current global rules, President Donald Trump's top trade negotiator said.

"There is one challenge on the current scene that is substantially more difficult than those faced in the past, and that is China," U.S. Trade Representative Robert Lighthizer said Monday in a speech in Washington. "The sheer scale of their coordinated effort to develop their economy, to subsidize, to create national champions, to force technology transfers and to distort markets in China and throughout the world is a threat to the world trading system that is unprecedented."

The World Trade Organization and the rules that underlie the international trade arbitrator weren't designed to deal with China's current approach to its economy, he said.