WASHINGTON (AP) — President Donald Trump's declaration of victory Monday in reaching a preliminary deal with Mexico to replace the North American Free Trade Agreement raised at least as many questions as it answered.

Can Canada, the third member country in NAFTA and America's No. 2 trading partner, be coaxed or coerced into a new pact?

If not, is it even legal — or politically feasible — for Trump to reach a replacement trade deal with Mexico alone?

And will the changes being negotiated to the 24-year-old NAFTA threaten the operations of American and foreign companies that have built sophisticated supply chains that span the three countries?

"There are still a lot of questions left to be answered," said Peter MacKay, a former Canadian minister of justice, defense and foreign affairs who is now a partner at the law firm Baker McKenzie.

Trump was quick to proclaim the agreement a triumph, pointing to Monday's surge in the stock market, which was fueled in part by the apparent breakthrough with Mexico.

"We just signed a trade agreement with Mexico, and it's a terrific agreement for everybody," the president declared. "It's an agreement that a lot of people said couldn't be done."

Trump suggested that he might leave Canada out of a new agreement. He said he wanted to call the revamped trade pact "the United States-Mexico Trade Agreement" because, in his view, NAFTA has earned a reputation for being harmful to American workers.