He added that Trump "can now go off and deal with China and deal with other people he wants to have trade wars with, and we are out of his gun sights for the time being".
"Most of effects ... have already been absorbed in Southeast Asia", he said. "It will strengthen the middle class, and create good, well-paying jobs and new opportunities for the almost half a billion people who call North America home".
Washington and Ottawa reached an agreement on Sunday after weeks of tense bilateral talks to update the 1994 North American Free Trade Agreement. But Congress and the legislatures in Canada and Mexico must still approve the deal. I believe in fair trade. "There are really no poison pills in here for Democrats". And, at one point, Trump's trade adviser Peter Navarro said there was "a special place in hell" for Trudeau.
"We are pleased a deal has been reached that preserves NAFTA's trilateral framework, which is critical to protecting North American supply chains that support millions of American jobs", said Matthew Shay, NRF president and CEO.
The agreement was reached late Sunday and gives US farmers greater access to the Canadian dairy market.
The deal does not include any changes to separate United States tariffs on steel and aluminum levied earlier this year on Canada, Mexico, China, the European Union and others.
Canada, the United States' No. 2 trading partner, is by far the No. 1 destination for USA exports, and the US market accounts for 75 percent of what Canada sells overseas.
"For those babies out there who keep talking about tariffs", this deal would not have happened without tariffs, Trump told reporters during a almost 80-minute event in the White House Rose Garden.
It "decreases US sovereignty", said Jeff Francer, general counsel for the Association for Accessible Medicines, a lobbying group for generic drug makers.
"On Tuesday, all the rumblings were that Trump and Trudeau were going to meet at the General Assembly - in fact, senior-level USA officials were telling stakeholders that at private dinners, luncheons, receptions in Canada and the US", the source said.
But there is a widely shared belief that Canada made concessions and the US did not.
Rather, the new agreement is being widely described as a "NAFTA-minus": a regime not as free as NAFTA had been, particularly in the automotive sector, but still very much in the interests of all three countries - and definitely better than no deal.
Prime Minister Justin Trudeau would only say it was a "good day for Canada" as he left a late-night cabinet meeting in Ottawa that capped several days of frenetic long-distance talks that included Foreign Affairs Minister Chrystia Freeland and U.S. Ambassador David MacNaughton. One of those lines was the way Canada ran its dairy sector.
The concessions are in theory a problem for Trudeau, whose ruling Liberals say they need to pick up seats in Quebec in an election set for October 2019 if he is to retain power.
The National Association of Manufacturers (NAM) in the United States declared itself "extremely encouraged" by initial details of the new three-way pact.
He tweeted: "It is a great deal for all three countries, solves the many deficiencies and mistakes in NAFTA, greatly opens markets to our farmers and manufacturers, reduces trade barriers to the USA and will bring all three great nations together in competition with the rest of the world".
"This administration is committed to strong and effective enforcement of this agreement", a senior USA official told reporters.