“I, for one, will not sit back and continue to let mercantilist trade practices continue to decimate American manufacturing and American jobs,” said Sen. Charles E. Schumer, New York Democrat.
The legislation, which faces a final vote likely later this week, enjoys strong support from Democrats but splits Republicans.
Sen. Bob Corker, Tennessee Republican, warned senators not to risk a trade war or treat the legislation as a warning shot. He said the currency bill imposed strict new rules without any flexibility.
“Is this what the United States Senate wants to do today?” he said.
Some lawmakers tied the China currency legislation to the trade agreements, saying the U.S. is poised to reassert an active role in the international economy.
Backers said the agreements could boost U.S. exports by $13 billion, while opponents said it could deepen the trade deficit by $16 billion and displace 200,000 workers.
Republicans have been begging for years for the administration to submit the deals for a vote, and Mr. Obama at various times seemed to agree, including mentioning it as an area of cooperation in his 2010 and 2011 State of the Union addresses.
But he repeatedly delayed, as he sought to sweeten the deal for American workers and to appease the concerns of labor union leaders, many of whom remain adamantly opposed to the agreements.
Mr. Obama himself, as a member of the Senate, voted against the Central America Free Trade Agreement in 2005. And during the presidential campaign in 2008 he said he opposed the Colombia agreement, arguing that violence against trade union leaders in that country showed Colombia did not have the kinds of protections needed for free but fair trade.
He also called the South Korea agreement “bad for American workers.”
But in 2010, Mr. Obama promised to double U.S. exports over five years, and his trade representative said the agreements were a top priority.