Deputy US Trade Representative Demetrios Marantis on Thursday urged China to follow through on commitments it made when it joined the World Trade Organization a decade ago. He says rampant Chinese violations on copywrited material cost US companies billions of dollars a year.

Marantis says the United States is prepared to file enforcement actions in the WTO if necessary. He says the US "will not negotiate indefinitely where US rights are concerned." US-China trade tension comes as the Obama administration attempts to get Chinese help settling nuclear standoffs with North Korea and Iran and important environmental and economic initiatives.