The United States-Mexico-Canada Agreement (USMCA) updates and replaces the nearly 25-year-old North American Free Trade Agreement (NAFTA)
The talks were being held over the phone, unlike in previous rounds where Canadian Foreign Minister Chrystia Freeland had traveled to Washington.
Momentum appeared to have stalled last week in efforts to bridge differences between Washington and Ottawa in negotiations to rewrite NAFTA, which began last year.
Officials have been in talks nearly non-stop for a month as they try to overcome hurdles and agree on a NAFTA rewrite.
The trade talks came after US President Donald Trump said on Saturday that there is "no political necessity" to keep Canada in the new NAFTA deal.
Trump's remarks raised doubts about whether the two countries can quickly reach a deal to keep Canada in the 24-year-old trading bloc, along with the United States and Mexico.
Optimism is high that the United States, Canada and Mexico are near the finish line for an agreement on a new North American Free Trade Agreement.
The three countries have been renegotiating NAFTA for over a year at the behest of Trump, who calls the 1994 trade pact a "terrible deal" that he blames for sending US manufacturing jobs to Mexico
Earlier today, a top Mexican official had told reporters a single issue remained to be resolved in US-Mexico talks, with Trump tweeting that "big deal" was at hand.
The Trump administration wants a higher percentage of auto production to come from within the NAFTA bloc before qualifying for duty-free status.