Canada and Mexico reject the U.S. hard line.

Canada and Mexico reject the U.S. hard line.

American negotiators asked to remove Mexico's long-haul industry from NAFTA cross-border services.

U.S., Canada, and Mexico would promise to avoid devaluing their currencies for competitive purposes.

U.S., Canada, and Mexico would promise to avoid devaluing their currencies for competitive purposes.

The potential dealbreakers are tempered by the pact's support in Congress.

Meeting the December target for a new agreement is unlikely, observers say.

Meeting the December target for a new agreement is unlikely, observers say.