HANGZHOU (AFP) - Ministers from the United States and China opened key trade talks Wednesday, with Washington looking to make progress on several disputes ahead of a visit by US President Barack Obama. US Commerce Secretary Gary Locke, Trade Representative Ron Kirk and Agriculture Secretary Tom Vilsack launched two days of talks with a team led by Chinese Vice Premier Wang Qishan in eastern Hangzhou, US officials said. The talks come less than three weeks before Obamas first presidential visit to China , and amid rising trade tensions between the two over US tariffs on Chinese tyre imports and a Beijing probe into US car products and chicken meat. I know the Chinese have some issues and we also have some issues, Locke told reporters at a pre-meeting briefing. Were hoping we will be able to make some considerable progress over the next day and a half in terms of some of these issues. Locke also said climate change and clean energy would be high on the agenda for the annual meeting of the US-China Joint Commission on Commerce and Trade (JCCT), which last convened in Yorba Linda, California, in September 2008. As the worlds two biggest emitters of carbon emissions, we also have a responsibility to act, Locke said. Washington and Beijing will be key players at the global climate change talks in Copenhagen in December, which will aim to hammer out a successor treaty to the Kyoto Protocol, which expires in 2012. Locke said clean energy projects were essential to keep our economies growing while preventing the catastrophic effects of climate change, but noted trade barriers had kept US firms out of new business opportunities in China . Locke said the value of the yuan would not be discussed during the talks, due to wrap up on Thursday. The US Treasury said earlier that the Chinese currency was undervalued, chiding Beijing for a lack of flexibility. Obama ignited the first major trade dispute of his presidency last month when he imposed punitive duties on Chinese-made tyres. Beijing retaliated by lodging a complaint at the World Trade Organization (WTO) and launching an investigation into possible unfair trade practices involving imports of US car products and chicken meat. Beijing has charged that Washingtons move violated WTO rules, but Obama has denied that it amounts to protectionism. And last week, the United States launched a probe on whether to slap almost 100 percent tariffs on steel pipes imported from China . Locke said there was a fine line between stimulating domestic industries and protectionism especially in the current difficult global economic climate. If countries engage in protectionism, it invites retaliation. Once we have retaliation, countries end up in a trade war. And in a trade war, no one wins, Locke said. The US trade deficit with China is the widest Washington has with any country, totalling 143.7 billion dollars in the first eight months of 2009, according to US data down 15.1 percent from the same period last year. Obama is due to visit China on November 15-18. He will go to Shanghai and Beijing, where he will hold a third set of talks with Chinese President Hu Jintao.