NAFTA talks are switching gears and slowing down as key obstacles emerge, with Canada and Mexico rejecting what they see as hard-line U.S. proposals and negotiators exchanging their strongest public barbs yet.

In the years leading up to the construction of an about $133 million port of entry in Tornillo, Texas, county leaders talked about the need for a bridge that would alleviate commercial traffic at other border crossings in El Paso.

U.S. negotiators on Oct. 12 presented a proposal for a so-called “sunset clause” that would see the North American Free Trade Agreement expire after five years unless the parties can agree to extend it, according to two people familiar with the talks.

A maddeningly slow inspection process that can make crossing the border an ordeal lasting as long as six hours for trucks carrying cargo from Tijuana to San Diego soon could be dramatically speeded up.