The looming renegotiation of the North American Free Trade Agreement is entering “the danger zone” as U.S. congressional representatives look to put their local trade disputes on the national agenda, according to MAAW Law Principal Mark Warner.

“If you are a congressperson elected in a district that has dairy concerns, or a state that has dairy, you are going to put that on the table no matter how much you love taking a selfie with the prime minister,” Warner told BNN in an interview on Monday.

The United States government is set to lay out its official objectives for NAFTA renegotiations as early as Monday. Congressional leaders will then be able to insert their own local trade demands into the pending negotiations, Warner noted.

“If you have a concern with dairy in Wisconsin or softwood lumber in the Pacific Northwest you are going to say, ‘Hmm, I want that in the negotiations,’” he said. “That’s the danger zone now because Congress will try to expand what’s put in front of them.”

On Friday, Prime Minister Justin Trudeau met with U.S. Vice-President Mike Pence and several key state governors at the U.S. National Governors Association’s summer meeting in Providence, R.I. He urged attendees to stand with Canada and not give in to “politically tempting shortcuts” on trade.

U.S. President Donald Trump repeatedly slammed NAFTA during last year’s election campaign, describing the 23-year-old trade accord as “the worst trade deal ever,” and vowing to either renegotiate it to the advantage of the United States or tear it up.

While the U.S. has been open about concerns with NAFTA, Canadian political leaders have been largely silent on what they want from the upcoming talks.