The US Senate Tuesday took a step toward ratification of the new trade pact with Mexico and Canada, but final timing remained in doubt amid an impasse over President Donald Trump's impeachment trial.

The Senate Finance Committee easily signed off on legislation to implement the US-Mexico-Canada Agreement weeks after it cleared the House of Representatives in a rare show of bipartisanship, and following years of international negotiations.

"I'm confident that this bill is going to make it to the president's desk," the panel's chairman Senator Chuck Grassley said shortly before the 25-3 vote in favor of ratification.

But lack of clarity over the looming impeachment trial has left USMCA timing up in the air.

Senate Majority Leader Mitch McConnell said in December that his chamber would likely turn to the USMCA only after completing Trump's trial on two articles of impeachment: abuse of power and obstruction of Congress.

With House Speaker Nancy Pelosi so far refusing to transmit the articles of impeachment to the Senate, McConnell stressed last week that senators could turn to "ordinary business."

The US-Mexico-Canada Agreement on trade has advanced in the US Senate but the timing of its final ratification was in doubt amid an impasse over President Donald Trump's impeachment trial
The US-Mexico-Canada Agreement on trade has advanced in the US Senate but the timing of its final ratification was in doubt amid an impasse over President Donald Trump's impeachment trial AFP / MANDEL NGAN

Complicating matters, the USMCA reportedly is being subjected to a procedural move that would require the bill to be referred to several other committees of jurisdiction for approval, which could delay a final vote by days or weeks.

"That's something I wasn't aware of until yesterday and I think that's going to be a problem," Grassley said, according to Politico.

Though the rewritten NAFTA was signed in 2018, House Democrats had held up the pact's ratification for a year, demanding greater assurances that Mexico could be held to its commitments to labor reforms called for in the agreement.

Most US lawmakers now appear to favor the bill, making it likely to win Senate approval, especially with Trump's support.

"A vote for USMCA is a vote for improved market access, more US manufacturing, and a more level playing field for American workers, farmers, and service providers," said Senator Rob Portman, from the Midwestern industrial state of Ohio.