Chinese Vice President Xi Jinping, center, speaks with U.S. Vice President Joe Biden and U.S. Secretary of State Hillary Clinton, at the State Department in Washington, D.C. at a luncheon in honor of the Chinese Vice President on Feb. 14. (Jim Watson/AFP/Getty Images)

America holds at least one key economic advantage over China, Vice President Biden said Thursday, declaring that because China’s authoritarian government represses its own citizens, they don’t think freely or innovate.

The comments came just two weeks after Biden hosted China’s presumptive next leader during Xi Jinping’s high-profile trip through the United States. During that visit, both sides stressed the potential for better relations and economic cooperation.

In his speech on Thursday, Biden asked students at Iowa State University, “Why have they not become [one of] the most innovative countries in the world? Why is there a need to steal our intellectual property? Why is there a need to have a business hand over its trade secrets to have access to a market of a billion, three hundred million people? Because they’re not innovating.”

Noting that China and similar countries produce many engineers and scientists but few innovators, Biden said, “It’s impossible to think different in a country where you can’t speak freely. It’s impossible to think different when you have to worry what you put on the Internet will either be confiscated or you will be arrested. It’s impossible to think different where orthodoxy reigns. That’s why we remain the most innovative country in the world.”

During Xi’s visit last month, Biden also criticized China, citing a long list of grievances against its government, including human rights violations, theft of intellectual property, China’s currency valuation and practices not in line with fair trade. But for the most part the visit was notable for the effort on both sides to find common ground and stress how the economies of the United States and China are intimately intertwined rather than competitive.

Much was made during the visit of U.S. food exports to China, with Agriculture Secretary Tom Vilsack joining Xi in Iowa for a symposium to talk soybeans and pork, and traveling with him to an Iowa farm, a visit that included photo-ops of China’s heir apparent in the seat of a John Deere tractor.

Biden also accompanied Xi to Los Angeles, using the city to highlight U.S.-China collaborations in the entertainment industry and commerce.

It isn’t the first time Biden’s off-hand comments on China have attracted attention. During his initial meeting with Xi, in a trip last year to China, Biden appeared to take a relatively untroubled view of China’s one-child policy.

In that case, he was speaking to students at Sichuan University in Chengdu, when he suggested that the one-child policy has eroded financial security for elderly Chinese.

“You have no safety net. Your policy has been one which I fully understand — I’m not second-guessing — of one child per family,” Biden said. “The result being that you’re in a position where one wage earner will be taking care of four retired people. Not sustainable.”

A few days later, the vice president’s office tried to correct the remarks, saying the Obama administration “strongly opposes all aspects of China’s coercive birth limitation policies, including forced abortion and sterilization.”