The United States said Thursday it was asking the World Trade Organization to settle a dispute with China over Beijing's duties on US chicken imports.

Ratcheting up pressure in tense trade relations between the world's two largest economies, the Obama administration said it was taking the "next step" in its more than year-long complaint against China in an bid "to protect American jobs."

"The United States will not stand idly by while China appears to have misused its trade remedy laws and put American jobs at risk," US Trade Representative (USTR) Ron Kirk said in a statement.

"We are serious about holding China accountable to its WTO commitments and ensuring that there is a level playing field for American businesses -- including our farmers."

Washington wants a WTO dispute settlement panel to address China's imposition of antidumping duties and countervailing duties on chicken 'broiler products' -- chickens less than 13 weeks old -- imported from the United States.

China imposed the duties beginning in August and September of 2010, claiming that the chicken products were subsidized and sold at less than fair value, or "dumped," into the Chinese market.

Prior to the duties, the United States was the largest exporter of broiler products to China. Since then US broiler chicken exports to China have fallen sharply, US officials said.

An estimated 300,000 US agricultural jobs are at risk from the impact of the duties, according to Kirk.

In September, the US asked the WTO to look at Beijing's allegedly unfair duties. Consultations were held with Beijing in late October "but were unable to resolve the dispute," the USTR said.

In requesting a WTO dispute settlement panel, Washington alleged that Chinese authorities failed to abide by applicable procedures and legal standards.

Those failures include finding injury to China's domestic poultry industry "without objectively examining the evidence, by improperly calculating dumping margins and subsidization rates, and by failing to adhere to various transparency and due process requirements," the USTR said.

The stepped-up US action to gain freer access to China's markets comes as President Barack Obama faces rising domestic political pressure over China's trade record from the Republican presidential field and in Congress.

Many in the United States blame Chinese trade and currency policies for the loss of jobs, particularly in manufacturing, and a massive trade gap.

With the unemployment rate at 8.6 percent, job creation is at the top of the agenda in the 2012 presidential campaign taking shape between Obama and his Republican foes.

Obama has targeted boosting exports to help the economy recover following a severe recession that ended in June 2009.