U.S. Trade Representative Robert Lighthizer leaves the room next to Canadian Foreign Minister Chrystia Freeland and Mexican Economy Minister Ildefonso Guajardo after a joint news conference on the closing of the seventh round of NAFTA talks in Mexico City, Mexico March 5, 2018. REUTERS/Edgard Garrido

(Reuters) - Canada’s government officials have expressed concern that a final North American Free Trade Agreement (NAFTA) pact will not be reached within the Friday deadline set by U.S. President Donald Trump, the Globe and Mail reported, citing a source familiar with the matter.

U.S. Trade Relations Representative Robert Lighthizer has refused to make any changes despite repeated efforts by Canadian Foreign Affairs Minister Chrystia Freeland to offer concessions to maintain an independent trade dispute mechanism in a revamped trade deal, the report said.

Top NAFTA negotiators from Canada and the United States wrapped up a third day of two-way talks on Thursday, agreeing to meet the next day to resolve final differences before a deadline.

Negotiations entered a crucial phase this week after the United States and Mexico announced a bilateral deal on Monday, paving the way for Canada to rejoin talks to salvage the 24-year-old accord that accounts for over $1 trillion in annual trade.