Vietnam has asked the World Trade Organization to appoint a panel of arbitrators to rule on a dispute over alleged dumping of Vietnamese shrimp on the U.S. market.
The escalation of the case is awkward for Washington as it attempts to strike a regional free trade deal with Vietnam while under domestic pressure from American shrimp producers to clamp down on Vietnamese imports.
Dumping, or damaging foreign competitors by exporting goods at unfairly low prices, is illegal under WTO rules.
But several WTO rulings have found that, until early last year, the United States was using the wrong method of calculating dumping, forcing the U.S. government to withdraw many of the accusations it had made.
However, Vietnam says the U.S. Department of Commerce has not reversed duties imposed to punish Vietnamese shrimp exporters.
