President Trump said that his administration would not have been able to renegotiate the North American Free Trade Agreement without threatening Canada and Mexico with tariffs.

"Without tariffs, we wouldn't be talking about a deal, just for those babies out there who keep talking about tariffs," the president said at a press conference announcing the new United States Mexico Canada Agreement Monday. "Without tariffs, we wouldn't be standing here ... right now."

The U.S. and Canada struck a last-minute agreement over the weekend that replaces the framework that has been in place between the U.S., Mexico and Canada since NAFTA was signed into law in the 1990s. The administration believes the new trade agreement will result in "freer markets, fairer trade and robust economic growth."

Trump used the ceremony Monday as proof that his tariff strategy is not only working, but that it is vital to renegotiating other trade deals, like those with China, the European Union and Japan. Trump said tariffs are a "powerful" tool, but that he doesn't necessarily have to use them.

[More: Trump heralds 'wonderful' non-NAFTA trade deal with Canada, Mexico]

The president hinted that he is open to levying tariffs on China and other nations, but that he has "feeling we will be successful" in renegotiating other trade agreements.

Five days before U.S. and Canadian officials reached an agreement, the president held a press conference in New York City where he was tough on Canada for their taxes on U.S. dairy products.

"We're very well along the way with Mexico. The relationship is very good. And with Canada, we'll see what happens. They're charging us 300 percent tariffs on dairy products. We can't have that. We can't have that," Trump said Wednesday.