Vermont's two U.S. senators on Thursday landed on opposite sides of a vote to approve an updated North American Free Trade Agreement. By an 89-10 vote, the Senate passed the trade pact, which President Donald Trump has dubbed the United States-Mexico-Canada Agreement.

Sen. Patrick Leahy (D-Vt.) backed the deal, calling it a reasonable compromise that would boost Vermont's export economy and dairy industry. But Sen. Bernie Sanders (I-Vt.) opposed it, arguing that it failed to address climate change and would not stanch the flow of American jobs to Mexico. The third member of Vermont's congressional delegation, Rep. Peter Welch (D-Vt.), voted for the deal when it passed the House last month.

The trade deal, which now goes to the president for his signature, was years in the making. First negotiated by the Trump administration, it was significantly revised last year in order to win support from the Democratic House. The pact won the support of many labor unions, including the AFL-CIO, but it was panned by environmental groups.

Sanders, who is running for president, explained his position Tuesday during a debate in Des Moines.

"The answer is, we could do much better than a Trump-led trade deal," he said. "This deal — and I think the proponents of it acknowledge — will result in the continuation of the loss of hundreds of thousands of good-paying jobs as a result of outsourcing." He noted that, in 1993, he had also opposed the original NAFTA.

Sanders also argued that it did nothing to stop climate change — and didn't even mention the phrase in its 2,000 pages. "Given the fact that climate change is right now the greatest threat facing this planet, I will not vote for a trade agreement that does not incorporate very, very strong principles to significantly lower fossil fuel emissions in the world," he said.

Sanders was the only presidential candidate in the Senate to oppose the deal. Sens. Michael Bennett (Colo.), Amy Klobuchar (D-Minn.) and Elizabeth Warren (D-Mass.) all voted for it.

In a statement delivered on the Senate floor, Leahy said that Vermont exported $1.3 billion in goods to Canada in 2018, or 43 percent of the state's exports. "Vermont is a border state, and the commercial and cultural exchanges with Canada are woven into the fabric of the state," he said. "Trade with our neighbors to the north is essential to Vermont, just as trade throughout North America is important to our national economy."

Leahy said the deal was particularly important to the state's dairy farmers because it would "increase U.S. access to markets in Canada and Mexico for our high-quality dairy products."

At the same time, Leahy called the agreement "far from perfect" and criticized its paucity of environmental enforcement regulations. "It is the greatest flaw of this agreement and a startling missed opportunity," he said.

Welch, who said little about the deal when he voted for it last month, said in a statement Thursday that it was "a vast improvement over the inadequate initial proposal by this administration."

He credited House Speaker Nancy Pelosi (D-Calif.) with negotiating key concessions. "While not perfect, on balance the final agreement merits support," Welch said.

Disclosure: Paul Heintz worked as Peter Welch’s communications director from November 2008 to March 2011.