Legislation that would help President Barack Obama seal a Pacific Rim trade pact cleared a procedural hurdle in the U.S. Senate on Tuesday, setting up a vote on the bill itself on Wednesday.
Senators voted 60-37 to limit debate on the legislation, which would streamline Congress' consideration of trade deals, including Obama's 12-nation Trans-Pacific Partnership.
"Today is a very big vote. It's an important moment for the country," said Senate Majority Leader Mitch McConnell, the chamber's top Republican, in urging support for Obama's trade agenda.
Obama needs fast-track authority to complete the 12-nation Trans-Pacific Partnership (TPP) trade deal, central to his signature foreign policy push to strengthen U.S. ties with Asia.
The legislation has already endured six weeks of congressional wrangling. It twice brushed with failure after revolts by Obama's own Democrats, many of whom fear trade deals will threaten U.S. jobs.
On the procedural vote, 13 of the chamber's 44 Democrats supported the legislation. They were joined 47 of the Senate's 54 Republicans, giving supporters of the legislation the 60 votes needed to proceed in the 100-member chamber. The bill itself now needs 51 votes to pass.
If all goes according to Republican leaders' plans, Congress also would send Obama this week a bill renewing an aid program for workers who lose their jobs as a result of trade deals.
The president wants both bills and he has left open the possibility of waiting for Congress to send him both before signing fast track into law.
Fast-track legislation would let lawmakers set negotiating objectives for trade deals, including the TPP, but it would restrict them to yes-or-no votes on final agreements.
After considering fast-track last month, the Senate was forced to debate the measure again this week after Democrats in the House of Representatives refused to approve the companion measure for workers.
Trading partners want fast-track enacted before finalizing TPP, the biggest trade deal since the North American Free Trade Agreement liberalized commerce between the United States, Canada and Mexico two decades ago.
Senators will vote Wednesday to limit debate on a second bill extending trade benefits to African nations, which now also contains the worker aid program.
The TPP, a potential legacy-defining agreement for Obama, would open markets for U.S. exporters like Intel Corp and Caterpillar Inc, extend monopoly periods for Pfizer Inc and rivals' medicines and cut import costs for companies like Wal-Mart Stores.
The vote came nearly two weeks after the U.S. House of Representatives defeated Trade Adjustment Assistance bill, another bill that would have facilitated the streamline process of Obama's trade pact.
The House voted 302 to 126 against the bill on June 12.
—CNBC contributed to this report.