OTTAWA - The federal government finds itself in a holding pattern on NAFTA negotiations with one-on-one talks between the United States and Mexico set to spill into next week.

A source familiar with the effort says Canadian negotiators won't be returning to the NAFTA bargaining table in Washington until its two partners find common ground on issues, especially the complex sticking points around the auto sector.

However, if the U.S. and Mexico can resolve their bilateral differences early next week, the source says Canada's team -- possibly including Foreign Affairs Minister Chrystia Freeland -- could rejoin negotiations later in the week.

Media reports say today's meeting between U.S. Trade Representative Robert Lighthizer and Mexican Economy Minister Ildefonso Guajardo ended with bilateral work still to be done.

Reports say Guajardo indicated the two sides have made progress and will meet again next week to continue their talks.

The U.S. and Mexican governments have both expressed optimism the entire NAFTA deal could be concluded before the end of the month.