With U.S. Treasury Secretary Steven Mnuchin admitting on CNBC that there are still some "significant" issues hindering a new NAFTA deal, CEOs like Union Pacific's Lance Fritz are concerned.

"I am worried about NAFTA just overall," Fritz told "Mad Money" host Jim Cramer on Tuesday. "What concerns me right now is there seems to be this idea that we've got to race to a deal, and if we can't get it done soon, we're going to have to pause for a while. And that strikes me as an unhealthy place to be."

Fritz, whose railroad company operates in Canada, Mexico and much of the Western United States, said that he has spoken to members of the Trump administration regarding NAFTA.

Last Thursday, Canadian Prime Minister said that he felt "positive" about trade talks with the United States, and Mexico's Economy Minister Ildefonso Guajardo said that the countries could strike a deal by the end of May.

U.S. lawmakers are pushing for a deal to be made quickly so they can approve it before a newly elected Congress takes its place in January 2019.

"I think we've got trading partners in Canada and Mexico who want to modernize NAFTA [and] we've all got good ideas about it," Fritz told Cramer. "I think there's a path forward to success for all of us to win and that's what I want to have happen."

Fritz emphasized the "inextricable links" between the trading economies of the United States, Canada and Mexico, saying that the trading bloc "is positioned to win globally" given the markets in which they operate.

"What we need is more markets available to us, not fewer," the CEO said. "Let's modernize the things that make sense, right? The dispute resolution system really does need to work a little better. We really do need to modernize around e-commerce and intellectual property, and there's a couple of other elements. But I think there's a clear path to win and I think it can happen."