The United States has filed a trade complaint against China for imposing duties on U.S.-made autos, the World Trade Organization (WTO) said on Thursday.

"We have now received formal notification from the U.S.," WTO spokesman Keith Rockwell told Reuters.

Earlier in Washington, a senior U.S. official said the United States would file a complaint against China on Thursday with the Geneva-based trade watchdog for imposing duties on more than $3 billion worth of U.S.-made autos.

President Barack Obama said that the new U.S. complaint against Chinese auto duties with the World Trade Organization is intended to "hold China accountable" for unfair trade practices that harm American automakers.

"Americans aren't afraid to compete," Obama said in a campaign appearance in the election battleground state of Ohio just hours after his administration lodged a case with the WTO against Chinese tariffs on U.S. auto exports.

"As long as we're competing on a fair playing field instead of an unfair playing field, we're going to do just fine," he said. "We're going to make sure that competition is fair."