Sen. Jeff Flake warned the White House against pulling out of the North American Free Trade Agreement, arguing that leaving the deal would harm the economy and lead to increased immigration. To think otherwise is an "illusion," he said on the Senate floor Thursday.

"Allow me to briefly describe what America would look like without NAFTA. It’s an America with fewer jobs and higher unemployment. Some of these jobs that are lost will not return for a generation, others will likely never return. It’s a poorer America. The gross domestic product will drop. Much of the positive growth we have seen recently will be erased," the Arizona Republican warned, adding later, "Let's not be fooled by those who would have us believe that the impact of exiting this trade agreement would somehow be minor or short-lived."

The U.S., Canada and Mexico have been renegotiating the deal for months. The latest round of talks is being held in Washington this week. The White House has proposed far-reaching revisions to the deal, such as allowing members to opt out of the dispute settlement system and raising the standard for what can be labeled "made in the U.S.A." Canada and Mexico have resisted the proposed changes, and the lack of progress has sparked fears among free-trade advocates such as Flake and the U.S. Chamber of Commerce that President Trump will follow through on earlier threats to pull the U.S. out of NAFTA.

Flake warned that doing so would not only hurt the U.S. economy but Mexico's as well, which will further hurt the U.S. "According to the Department of Homeland Security, the number of people caught trying to illegally cross the border from Mexico has fallen to the lowest level in 46 years. However, if we pull out of NAFTA and allow Mexico to plunge into chaos and uncertainty it will undoubtedly drive that number up as more and more of their citizens flee to America. These are the real ramifications of terminating NAFTA."