Foreign Affairs Minister Chrystia Freeland is skipping an important diplomatic trip to Brussels to stay in Washington as NAFTA talks intensify.

The minister’s decision suggests that NAFTA negotiations may have hit a critical point, with some reports suggesting that there is a push by officials to hammer out a deal by next Tuesday. That’s when U.S. steel and aluminum tariffs -- which Canada is exempt from -- take effect.

Freeland briefly spoke with reporters as she entered the U.S. trade building on Thursday and confirmed that she will not attend a meeting of NATO foreign ministers in Belgium.

"I think it's important for us to keep on working at this," Freeland said.

Recent signals suggest that the negotiations are heating up. Negotiators stayed locked in closed-door meetings throughout last weekend. Last week, Freeland said that new rules on autos are at the “heart” of the negotiation, adding, "If we can get that right, that will be the core of a successful agreement."

UNIFOR president Jerry Dias, who is in Washington, D.C., amid the negotiations, said there is “certainly some movement” on the auto talks, and he didn’t dismiss the idea that a big break could be soon.

“There’s no question, there’s full-court press going on here. If you take a look at the Canadian embassy, there’s a who’s-who of Canadian politics here. So people are determined. And the Canadian team, I give them full credit. They’re being very constructive, progressive,” Dias told CTV’s Power Play on Thursday.

Still, Dias said there are kinks to iron out. He says U.S. negotiators are still intent on eliminating Chapter 19, NAFTA’s existing dispute-mechanism system, in favour of hearing all cases in U.S. courts.

Dias called the idea “a foolish proposal.”

“Since NAFTA (talks) started in August of last year, they came after us on softwood lumber, paper, aerospace, steel, aluminum. So for Canada to even contemplate allowing all disputes to be handles on U.S. soil, is a non-starter,” he said.

“There’s just so many foolish issues on the table that the United States isn’t moving on. That’s why I think an imminent deal is certainly pushing it.”

If a deal isn’t reached in the next week, Dias said he doesn’t think that would spell NAFTA’s demise.

“No, I don’t think it’s dead. But I think that everybody can take a deep breath and re-engage when it makes sense. Ultimately, Canada doesn’t need to buy into a bad deal, and I don’t think they’re going to do that.”

According to The Canadian Press, U.S. negotiators are engaged in an “all-out push” to reach an agreement by next Tuesday. The U.S. trade czar is expected to leave for China then, and the new U.S. tariffs on steel and aluminum also begin.

Sources told the Canadian Press that negotiators are split over introducing a sunset clause into NAFTA, and disputes continue over intellectual property and public procurement.

Mexico's economy minister, Ildefonso Guajardo, said he will remain in Washington for the ongoing talks.

"We're trying to do our best, but there are still a lot of things pending. ... We are (working) on all the topics. Auto rules, intellectual property. Everything is on the table," Guajardo said.

The NATO meeting would have marked Freeland’s first meeting with the new U.S. Secretary of State Mike Pompeo, who was sworn in Thursday.

With files from CTV News' Richard Madan and The Canadian Press