Updated 2:01 p.m. | President Donald Trump on Monday hailed a trade pact that could replace the North American Free Trade Agreement, but the fate of the deal is soon to pass into the hands of Congress, and lawmakers have their own concerns.

And a top author of the deal says there is no major flaw to prevent Democrats from supporting it.

The president said he intends to sign and send the agreement to Congress by the end of next month. He said it should sail through Congress “but anything you send to Congress is trouble.”

U.S. and Canadian officials announced late Sunday evening that Canada had agreed to join a revised NAFTA based largely on terms the United States and Mexico brokered in August and are based on what the president insists be “fair” deals for the United States.

In his typical fashion, the president said the trilateral deal might be the most important trade pact in American history “by far.” But lawmakers must first agree, and a possibly Democratic-run House — and possibly Senate, if that party takes one or both chambers in the midterms — could determine if Trump’s characterization is correct.

Negotiators from the three countries made late changes to get Ottawa into the deal. U.S. lawmakers from both parties had warned Trump and his team to find a way to include Canada, with White House officials acknowledging congressional approval would be easier with a three-way deal.

Still, officials and experts expect a fight awaits Trump and White House officials to garner approval from both chambers.

White House officials contend the deal, if approved by Congress, would benefit American dairy farmers and automakers. They also have highlighted new e-commerce and intellectual property protections, as well as a new six-year review mandate.

United States Trade Representative Robert Lighthizer, who was instrumental in the deal, predicted the agreement would pass both chambers “with a substantial majority.”

“There are no poison pills for Democrats,” he told a group of reporters following Trump’s remarks. Lighthizer repeatedly pointed to labor provisions intended to help American workers and environmental standards as examples of things Democrats should like about the pact.

The top trade negotiator said he has talked with Democratic members about the deal, including ones who sit on the crucial Ways and Means and Finance committees.

“I don’t go literally a day” without talking to lawmakers about the U.S.-Mexico-Canada trade talks, he added.

And, notably, he said Trump instructed the U.S. trade team from the start to negotiate terms that would be attractive to members of both parties — not just the White House’s GOP allies.

Among the GOP lawmakers at the Rose Garden ceremony were House Freedom Caucus Chairman Mark Meadows of North Carolina and Sen. Joni Ernst of agriculture-rich Iowa.

After months of tension, Trump applauded Canadian Prime Minister Justin Trudeau, saying the deal is “terrific” for both countries.

The GOP president lightly criticized Democrats for either criticizing the new pact or not voicing support. But he said it is so good he expects they will change their tune “by tomorrow.”

He signaled he expects many Democratic members will oppose the pact because “Trump likes it … therefore we can’t approve it.”

Democrats, however, have deep concerns over its lack of labor and environmental standards for which they had pushed.

“I will be carefully reviewing the new draft agreement released last night to ensure that American workers will see higher wages and have access to new economic opportunities; that it protects the rights of workers and organized labor that Democrats have fought to secure and defend; that it includes environmental protections; and that any new obligations in these areas will be strictly enforced. Congress must carefully consider any new trade agreement based on how it meets these criteria,” House Minority Whip Steny H. Hoyer, D-Maryland, said in a statement. 

The president issued a promise of sorts, predicting the United States, if the deal is formally adopted, will be “manufacturing more automobiles.” And he described it as a “privilege” for friends and foes alike, including China, to sell their goods here.

Trump offered a preview of several campaign rallies on his schedule this week, saying without his tariffs on foreign goods “we wouldn’t be standing here.”

He often rails against previous administrations’ trade policies and slams other countries’ tactics at such events. His supporters typically respond with loud applause.

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