WASHINGTON — The Senate passed legislation Wednesday that would nullify U.S. tariffs on Canada, just as President Donald Trump is engaged in trade talks in Asia as well as an increasingly bitter trade spat with U.S.’s northern neighbor that is one of its largest economic partners.

The 50-46 tally was the latest in a series of votes this week to terminate the national emergencies that Trump has used to impose tariffs.

While the resolutions won’t ultimately take effect, they have proven to be an effective way for Democrats to expose cracks between the president’s trade policy and Republican senators who have traditionally supported free trade arguments.

Sen. Tim Kaine of Virginia, the Democrat pushing the resolutions, said that higher prices caused by tariffs would force Republicans to break with Trump.

“It will become untenable for them to just close their eyes and say, ‘I’m signing up for whatever the president wants to do,’” Kaine told reporters.

The Senate passed a similar resolution applying to Brazilian tariffs Tuesday, and it has already passed a resolution on Canadian imports in April. The same four Republicans — Sens. Sens. Lisa Murkowski of Alaska, Susan Collins of Maine, Mitch McConnell of Kentucky and Rand Paul of Kentucky — voted again with all Democrats to approve the resolution applying to Canada.

Kaine, joined by other Democrats and Paul, has forced the votes under a decades-old law that allows Congress to block a president’s emergency powers. However, House Republicans have passed new rules that allow leaders to prevent such resolutions from getting a vote in that chamber, and Trump could veto the legislation even if it did clear Congress.

Wednesday’s vote happened as Trump was in Asia to advance trade talks with partners there. The president has also been jousting with Canadian officials amid a delicate negotiation to reduce tariffs between the two countries.

Sen. Mike Crapo, the Republican chair of the Senate Committee on Finance, acknowledged in a floor speech that many “may be nervous about what comes next” as Trump remakes global trade. But he urged Congress to stay out of the way.

“Let’s truly get a balanced, fair playing field in trade,” Crapo added.