Under the pressure of the election year and high unemployment, some US senators proposed legislation on Tuesday to press China to appreciate its currency.

Five senators introduced the Schumer-Stabenow-Graham Currency Exchange Rate Oversight Act of 2010 at a press conference at the Capitol Hill.

Democratic Senator Chuck Schumer said that China's currency renminbi is undervalued and he has kept pushing the US government to press China to strengthen its currency.

The Schumer bill requires the US Treasury Department to identify countries with "fundamentally misaligned currencies" and asked the Commerce Department to investigate currency undervaluation as a "countervailable subsidy."

The United States recently ratched up pressure on China to realign its currency. On Monday, 130 US congressmen wrote to the government, demanding the Obama administration take actions to appreciate yuan against the dollar.

China has dismissed calls for revaluation of its currency. The country's managed floating exchange rate system, in place since July 2005, is market-based, said Chinese Commerce Ministry spokesman Yao Jian on Tuesday.

"It would be unfounded and meaningless for some people in the United States to back their calls (for China to be labeled a currency manipulator) by citing China's trade surplus and US deficit and the US recovery needs," Yao said.