U.S. President Barack Obama said late on Sunday that China was now a \"grown-up economy\" and should act more responsibly on its currency as the undervalued yuan was hurting American companies and jobs. \"We welcome China\'s peaceful rise,\" but Beijing should stop \"gaming\" the international economic system and create a level playing field for U.S. and other foreign businesses, Obama said at the end of an Asia-Pacific Economic Cooperation (APEC) summit in Honolulu. Obama insisted that China continued to keep its national currency at an artificially low level to create advantages for Chinese exporters. \"Most economists estimate that the renminbi [yuan] is devalued by 20 to 25 percent. That means our exports to China are that much more expensive and their imports into the United States are that much cheaper,\" Obama said. In early October, the U.S. Senate passed a legislation to prompt China to let its currency rise more quickly in value. China has insisted, however, that the yuan should rise gradually to avoid harm to its economy and prevent a rise in unemployment, which could affect global growth. \"There has been slight improvement over the last year partly because of U.S. pressure but it hasn\'t been enough. It is time for them to go ahead and move towards a market based system for their currency,\" Obama said. The United States has had a trade deficit with China, its second largest trading partner, since the early 1990s. As U.S. imports from China have risen more rapidly than U.S. exports to China, the U.S. trade deficit has soared from some $10 billion in 1990 to $273 billion in 2010. \"We\'re going to continue to be firm that China operate by the same rules as everyone else,\" Obama said.