Canada’s ambassador to the United States said he doesn’t see any reason why a new North American Free Trade Agreement can’t be renegotiated quickly, as long as all sides want it to get done.

“We’re prepared to work 24-7 to get a deal done, but if you’re going to have a quick deal, it means that everybody’s got to show a little flexibility,” David MacNaughton told BNN Bloomberg in an interview on Thursday. “We’re prepared to show some flexibility and we would hope that the Americans would too. And if everybody comes to the table, rolls up their sleeves and gets down to work, and there’s a give and take, then I think we can get it done pretty quickly.”

MacNaughton expressed optimism that negotiations could pick up steam if the U.S. and Mexico reach an agreement on automotive rules at their talks in Washington this week. Bloomberg News reported Wednesday that the two sides are targeting an agreement on cars by the end of this week.

“There are still some bilateral issues between Canada and the U.S. and between the U.S. and Mexico that need to be resolved outside of autos, but if the auto thing gets resolved then I think we’re well on our way to a successful modernization,” MacNaughton said, adding that U.S. President Donald Trump’s concerns about his country’s trade deficit with Mexico could be assuaged by reaching common ground on cars.

However, MacNaughton reiterated that the contentious sunset clause proposal and the need for a dispute resolution mechanism remain Canada’s greatest concerns in reaching a new deal, flagging the former as a major driver for investor certainty.

“There are a number of different categories of issues where we have differences of opinion,” MacNaughton said. “The most important, from our perspective, is that you need to have some kind of certainty for investment purposes, which is why we don’t like the automatic termination of the agreement unless all three parties agree to keep it going after five years.”

MacNaughton also said that Canada’s diplomatic relationship with the United States remains strong, despite Trump’s recent tariff tactics.

“I think there’s no doubt that when they introduced the [Section] 232, the so-called ‘national security’ issue on steel and aluminum, that was a bit of a shock to the system,” MacNaughton said.

“Are there differences of opinion? [Has] there been some drama and some bumps along the way? For sure. But we don’t have any problem in terms of access to our American counterparts.”