1. “This is a really big deal.”

Canada’s foreign minister, Chrystia Freeland, above, said they were moving “full steam ahead” to try to save a trilateral agreement on a revised North American Free Trade Agreement. Ms. Freeland said she was “encouraged by the progress that the U.S. and Mexico have made, particularly on cars and labor.”

The last-ditch discussions came a day after the Trump administration announced it had revised the North American Free Trade Agreement with Mexico and threatened to leave Canada out, which could leave its economy reeling.

Ms. Freeland must decide by Friday whether to join the revised pact.

So far, the biggest changes deal with how to avert automobile tariffs, a topic closely watched around the world.