BEIJING - China here Tuesday expressed firm opposition on the US Senate's bill on Chinese yuan after it voted to allow a debate on the bill on so-called "currency manipulation" by China.

Such a move "seriously violates rules of the World Trade Organization and obstructs China-US trade ties," Foreign Ministry spokesman Ma Zhaoxu said in a statement.

China demands certain US Senators to "rationally savvy the Sino-US trade cooperation, which is mutually beneficial in nature, and stops to pressure China by using domestic law-making means of the United States," he said.

The 79-19 vote in US Senate opened a week-long debate on the bill.