(CNN) The United States and Mexico have reached an agreement to change parts of NAFTA, the trade deal that President Donald Trump has derided for years as unfair.

Trump announced the agreement from the Oval Office Monday, with Mexican President Enrique Peña Nieto dialed in on a conference call.

But the deal left open the question of whether Canada, the third country in NAFTA, would agree to the changes -- and Trump himself said he wanted to throw out the name NAFTA altogether.

"They used to call it NAFTA," Trump said. "We're going to call it the United States-Mexico trade agreement. We're going to get rid of NAFTA because it has a bad connotation."

US Trade Representative Robert Lighthizer said the agreement was "absolutely terrific" and would modernize a trade deal that had "gotten seriously out of whack." He said he hoped Congress would approve it with broad bipartisan support.

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