There are more ruffled feathers in the trade dispute between China and the U.S. on chicken exports. The US Trade Representative's office claims now that China's anti-dumping and countervailing duties violate WTO rules.

The US Trade Representative says China didn't calculate US poultry production costs correctly and there's no evidence that American exports have hurt Chinese producers.

China's Ministry of Commerce says it regrets the U.S. action but will resolve the dispute in accordance with WTO processes.

The dispute marks the second time that the US has objected to Chinese trade remedies against U.S. broiler chickens. China lowered its duties on U.S. broiler chickens in 2014 after the WTO accepted U.S. arguments.