U.S. Treasury Secretary Jacob Lew Monday pressed China to speed up the liberalization of the renminbi ahead of the two countries' economic conference next month. Lew told Vice Premier Wang Yang of "the need for China to move more rapidly toward a market-determined exchange rate" in a telephone discussion, the Treasury said in a statement. The United States says that the renminbi is deeply undervalued and needs to float according to market forces to help right the two-way trade gap, which is deeply skewed in China's favor. The two officials spoke Monday on the bilateral economic relationship generally and on preparations for the U.S.-China Strategic and Economic Dialogue, to take place in Beijing in early July. The annual dialogue brings together top policymakers and experts from the two superpowers to discuss commonalities and differences on key global and bilateral issues.