President Obama today stepped up efforts to enforce U.S. trade rights with China, announcing new plans to challenge China's export limits on rare earth and other minerals key to high-tech manufacturing.

"We want our companies building those products right here in America. But to do that, American manufacturers need to have access to rare earth materials which China supplies," the president said at the White House Rose Garden.

"Now, if China would simply let the market work on its own, we'd have no objections. But their policies currently are preventing that from happening. And they go against the very rules that China agreed to follow," he said.

In an effort to level the playing field, the United States, Japan and the European Union are pressing the World Trade Organization to force China to ease its restraints on exports of rare earth, which is crucial to the production of hybrid batteries, wind turbines and cell phones.

The president cast the move as part of his broader effort to enforce global trade rules.

"Our competitors should be on notice: You will not get away with skirting the rules," he said. "When we can, we will rally support from our allies. And when it makes sense to act on our own, we will."

The White House action comes as the president faces election-year attacks from his Republican rivals for not being touch enough on Beijing. While the administration prefers dialogue to tackle trade issues, the president made clear today that "when it is necessary, I will take action if our workers and our businesses are being subjected to unfair practices."

The administration denied politics were involved in today's announcement.

"The fact is we've been at this for three years because it's the right thing to do," White House Press Secretary Jay Carney told reporters.