"China will not end its currency undervaluation unless the U.S. seizes opportunities like this to insist that it does," the lawmakers said in a letter to Treasury Secretary Timothy Geithner and U.S. Trade Representative Ron Kirk.
"Expanding and intensifying discussions at the WTO can further this effort and bring significantly more pressure to bear on China," they said.
The letter was signed by Senate Finance Committee Chairman Max Baucus, a Democrat, and House of Representatives Ways and Means Committee Chairman Dave Camp, a Republican.
The U.S. Trade Representative's office deferred questions on the issue to the Treasury Department, which traditionally takes the lead on currency matters.
The Treasury Department said addressing the undervaluation of the Chinese currency was a top priority.
"We will continue to press at every opportunity for policy changes that yield greater exchange rate flexibility, level the playing field for our workers and businesses, and support a pronounced and sustained shift to domestic demand-led growth in China," a Treasury spokesperson said.
Many U.S. lawmakers say China significantly undervalues its currency to give its companies an unfair price advantage in international trade.
Last year, the Democratic-controlled Senate passed legislation to allow the Commerce Department to treat currency undervaluation as an illegal subsidy so that countervailing import duties could be imposed.
However, the measure has languished in the House, where Republicans have a majority and their leaders have refused to bring it up for a vote on the grounds that it could start a trade war.
The WTO has begun an examination of the relationship between exchange rates and trade.
Its secretariat has concluded a survey of literature on the topic, and the WTO will hold a symposium on March 27-28 for countries to air their views.
Baucus and Camp said the symposium would benefit the United States by illuminating how current WTO agreements could potentially be used to "address distortive currency practices."
Some lawyers have argued that one WTO measure - which says "parties shall not, by exchange action, frustrate the intent of the provisions of this agreement" - could be used by the United States to challenge China's currency regime.
Senator Orrin Hatch, the top Republican on the Senate Finance Committee, in a Jan. 18 letter made available on Monday, also raised the currency issue with Geithner and Kirk.
He asked the Obama administration to provide by March 5 a summary of the position it will present at the symposium, a list of people who will be representing the United States and "what the administration seeks to achieve" at the meeting. (Reuters)
