U.S. Republican presidential candidate Mitt Romney continued his tough talk on China Monday, mocking Beijing's plans to send an unmanned rocket to the moon.

At a campaign speech in Florida, Romney also boasted about the success of the U.S. Olympic team, which finished with 16 more medals than second-place China.

“This is still the greatest nation on Earth. I know there are people around the world who are always critical of America, have something negative to say, say our greatest days are in the past. Baloney. We just won more Olympic medals than any other nation on Earth. You also just saw we just landed on Mars and took a good look at what's going on there. And I know the Chinese are planning on going to the moon, and I hope they have a good experience doing that. And I hope they stop in and take a look at our flag that was put there 43 years ago.”

During his campaign, Romney has taken a firm stance on issues that have recently tested U.S.-China relations, including disputes over trade, intellectual property, and currency value.

Beijing has dismissed such statements as irresponsible and politically motivated, and has suggested they could hurt relations between the world's two largest economies.

Romney has repeatedly threatened to designate China as a currency manipulator and impose sanctions against it if he is elected. In his speech Monday, he made similar comments.

“We also need to crack down on nations that cheat and don't play by the rules. When China steals our technology, when China steals our intellectual property, our patents and designs, our know-how, when they manipulate their currency, we're going to say, 'no-more.' Cheating must have consequences.”

Many in the U.S. and Europe accuse Beijing of intentionally keeping the value of its yuan currency low, giving its exporters an unfair advantage in international markets.

President Obama has accused China of “gaming” the global trading system, but has stopped short of calling for it to be officially labeled as a currency manipulator.