Democratic presidential hopeful Barack Obama warned on Wednesday China had “played” the United States on trade and said he was in “two minds” whether America should play a full role in the Olympics.The Illinois senator said he was a “strong believer” in free trade, but believed that US negotiators had not been tough enough in their dealings with Beijing.“I think that we have not been very savvy negotiators when it comes to China. I think they’ve played us,” Obama told CBS News, three weeks before the next Democratic nominating contest, the Pennsylvania primary.“They definitely are stealing our intellectual property and that has direct consequences in terms of the bottom lines for businesses here in the United States.” Trade has been a key issue in the Democratic White House race, especially in relation to the flight of blue collar manufacturing jobs to China and other Asian markets with low labor costs.Obama was also asked whether the United States should be a full participant in this year’s Beijing Olympics, as global concern mounts about the communist giant’s human rights record and crackdown in Tibet.“I’m of two minds about this. On the one hand, I think that what’s happened in Tibet, China’s support of the Sudanese government in Darfur, is a real problem,” Obama said.“I’m hesitant to make the Olympics a site of political protest because I think it’s partly about bringing the world together.” Obama spoke a day after some US lawmakers introduced a bill designed to President George W Bush to skip the Olympics opening ceremony.