"That being said, I think we have a short window here, where we can come together and do a deal in principle," added Heyman, who served under President Barack Obama from 2014 to 2017.
Canada's foreign minister traveled to Washington to resume negotiations with the United States, following Monday's deal between the U.S. and Mexico, which serves as a start to replace the 1994 North American Free Trade Agreement among the three nations.
"We will have a deal with Canada," Trump said during a news conference on Monday. "It will either be a tariff on cars, or it will be a negotiated deal."
Heyman said he thinks "there is a path" toward compromise with Canada, especially since Ottawa has previously demonstrated some willingness to ease dairy industry restrictions.
Canada and Mexico both want a formal provision on how to resolve particular disputes worked into any new trade agreement, but the U.S. would prefer to deal with problems on a less-formal basis.
Earl Anthony Wayne, who was U.S. Ambassador to Mexico under Obama and U.S. Ambassador to Argentina under President George W. Bush, agreed that dispute resolution would be a key component of any new agreement.
"There have been a number of changes in the dispute settlement proposal, so companies and certain sectors will be concerned about that," said Wayne, in the same "Squawk on the Street" interview as Heyman.
Wayne highlighted as areas to watch, the impact of new rules on North American auto industry competitiveness, labor requirements and industry stakeholder commentary.
"A number of congressmen have already spoken out saying, 'It's really important that this final agreement be trilateral and we're not sure that we would approve it if it's not,'" Wayne said.
Heyman warned against the U.S. punishing Canada too hard. "We need to make sure that if the next three days don't go well, that the United States doesn't start beating on Canada and do all of the things that the president was threatening on auto tariffs and the like, or this [stock] market will turn around very quickly."