U.S. Treasury Secretary Jacob Lew said on Tuesday that China's yuan currency is still undervalued as it has only appreciated 14 percent since 2010. Lew will raise the currency issue at the U.S.-China Strategic and Economic Dialogue (SED) in Beijing next Monday and Tuesday, in which he will lead the U.S. delegation with U.S. Secretary of State John Kerry. The value of the yuan is a highly sensitive political issue for the two economies, and at in event in Washington Lew said, "it's fundamentally not fair in terms of trading practices." Lew said the yuan should trade at a market-determined foreign exchange rate and expressed frustration at the slow pace of economic reforms in China's third plenum.