Senate Democrats signaled more challenges to President Donald Trump's emergency declarations at a press conference ahead of a forced floor vote to undo his tariffs against Canada.

"One at a time," Sen. Tim Kaine, D-Va., told reporters on Wednesday when asked if we would also be introducing a privileged resolution canceling Trump's emergency declaration in Mexico.

"Let's get this one done. And if we can get this one done and succeed, then we also have to see what President Trump does this afternoon," he explained, referencing the president's planned remarks on tariffs at 4 p.m. in the White House's Rose Garden.

"There may be a whole new series of trade or tariff-related motions coming your way soon," the Virginia Democrat said.