Trump's remarks follow a refusal by Trudeau to accept terms laid out by the U.S. administration.
"The United States has been taken advantage of for many decades on trade. Those days are over," Trump said late Thursday.
"This message was conveyed to Prime Minister Justin Trudeau of Canada: The United States will agree to a fair deal, or there will be no deal at all."
On Friday, Trump demanded Canada "open their markets and take down their trade barriers."
"Canada has treated our Agricultural business and Farmers very poorly for a very long period of time," the president said in a tweet. "Highly restrictive on Trade!"
Earlier Thursday, Trudeau announced retaliatory tariffs in response to U.S. duties on steel and aluminum made in Canada, Mexico and European Union nations.
"American tariffs on Canadian aluminum and steel are unacceptable," Trudeau said in a statement. "We will always stand up for our workers."
Trudeau also canceled plans to visit Washington to finalize a new NAFTA deal after Vice President Mike Pence demanded that any deal would last just five years. The Canadian leader told Trump in a phone call he would not sign an agreement with such a "sunset clause."
"Americans remain our partners, friends, and allies," Trudeau said. "This is not about the American people. We have to believe that at some point their common sense will prevail. But we see no sign of that in this action today by the U.S. administration."
Trump has repeatedly threatened to junk the 1994 trade agreement unless it's renegotiated to fix what he says are terms unfavorable to the United States.
"FAIR TRADE!" read one tweet by Trump Thursday.