Canadian Prime Minister Justin Trudeau tried to lay out his preferred terms for the renegotiation of the North American Free Trade Agreement as demanded by President Trump, delivering the keynote speech at a gathering of the National Governors Association on Friday.

Trudeau came to the NGA meeting in Providence, R.I., to emphasize to America's governors the economic benefits that he says NAFTA has provided to the U.S., Canada and Mexico. He said renegotiating the agreement should lead to a "thinner border for trade, not a thicker one."

"Sometimes getting it right means refusing to take the politically tempting shortcomings," Trudeau said, according to the Washington Post.

He warned new trade barriers could be harmful to the three North American countries.

"Once we travel down that road, it can quickly become a cycle of tit for tat, a race to the bottom where all sides lose," Trudeau said.

The Canadian prime minister said he welcomes a NAFTA renegotiation, but wants the end result to open up more trade opportunities.

"NAFTA isn't perfect," Trudeau said. "No such agreement ever is. We think it should be updated and modernized, as it has been a dozen times over the past quarter-century."

Trump promised during the campaign to either repeal or renegotiate NAFTA, which he decried has one of the worst trade agreements the U.S. has negotiated.

Earlier this year, it appeared he might abandon the agreement, but after phone calls from Trudeau and Mexican President Enrique Peña Nieto, he agreed to a renegotiation.

Trudeau, the first foreign leader of his stature to address the gathering of governors, told his audience that two-thirds of U.S. states consider Canada as either their first- or second-most important trade partner.

"Canada is the U.S.'s biggest, best customer by far," Trudeau said. "No one even comes close."