WASHINGTON -- Canadian negotiators are travelling to brief Prime Minister Justin Trudeau in person on the state of negotiations with the United States on a deal that would allow Canada to remain in a North American trade bloc.

Canada's envoy -- Foreign Affairs Minister Chrystia Freeland -- left a meeting with U.S. Trade Rep. Robert Lighthizer Tuesday night. She said the talks were at a point where discussing them face-to-face with the prime minister "is absolutely essential."

Trudeau and his ministers will hold a caucus retreat in Saskatoon, Saskatchewan, to plot their strategy.

The U.S. and Mexico last month reached a preliminary agreement to replace the 24-year-old North American Free Trade Agreement. But those talks excluded Canada, the third NAFTA country.