NAFTA talks are entering a pivotal moment as the U.S. turns up the pressure on Canada and Mexico to radically alter the trade pact in favor of American interests.

Investors remain on alert over the threat of Nafta talks failing even as negotiators meet this week in Washington and seek minor victories on less contentious issues.

The ministers leading NAFTA negotiations ended the latest round of high-level talks saying they’re extending discussions into the first quarter of 2018 to resolve differences after Canada and Mexico rejected what they see as hardline U.S. proposals.