BEIJING (AP) -- China's premier rejected foreign pressure over its exchange rate controls and said Sunday the Chinese currency will be kept "basically stable." Premier Wen Jiabao promised to reform currency controls, but gave no indication when that might happen. Washington and other trading partners are pressing Beijing to ease controls that they say keep the yuan -- also called the renminbi -- undervalued, giving its exporters an unfair price advantage and swelling its trade surplus. "First of all, I don't think the renminbi is undervalued," Wen said at a news conference. "We oppose all countries engaging in mutual finger-pointing or taking strong measures to force other nations to appreciate their currencies." Some American lawmakers and trade groups want Congress to impose punitive tariffs on Chinese goods if Beijing fails to act. Critics say the yuan is undervalued by up to 40 percent against the dollar.