The decision came as the world's two biggest economies try to clinch Phase 1 of a trade deal. President Donald Trump and U.S. negotiators are "very optimistic" about concluding it, White House adviser Larry Kudlow said.
In the WTO ruling, a three-member arbitration panel said Chinese exporters suffered impairment to trade valued at $3.579 billion annually. China may now ask the WTO's Dispute Settlement Body for a green light to impose the retaliatory tariffs on imported U.S. goods valued up to that amount each year.