BEIJING: Beijing needs to take seriously American concerns about the value of the Chinese currency, but bilateral disputes should not impede cooperation on global issues such as climate change and Iran's nuclear programme, the US ambassador to Beijing said today.

Washington and other trading partners are pressing China to ease currency controls that have kept its yuan steady against the dollar for 18 months to help their companies compete amid weak global demand.

A group of American lawmakers wrote to President Barack Obama this week urging him to press Beijing to loosen controls. The US Treasury has the option of declaring Beijing a currency manipulator in a report due out in April, which could set the stage for a complaint to the World Trade Organisation and possible sanctions on Chinese goods.

"This is a real concern for people in my country," Jon Huntsman told students at Beijing's elite Tsinghua University, citing high US unemployment that critics say is exacerbated by an undervalued yuan.

China insists the United States is responsible for bilateral tensions and Chinese Foreign Ministry spokesman Qin Gang responded to Huntsman's comments by saying he hoped they would be "translated into concrete actions."

The sharpening trade disputes come amid lingering Chinese anger over US arms sales to Taiwan and a recent meeting between Obama and Tibet's exiled spiritual leader, the Dalai Lama.

However, Huntsman said such differences "cannot, must not, prevent the two countries from working together." "To put our relationship on a more stable and mature footing, we have to delink our differences on bilateral issues from our cooperation on global issues, including nonproliferation," he said. Huntsman said China has much at stake in the debate over Iran, having imported more oil from Saudi Arabia last year to fuel its economy than the US did.