Trump offered up the stinging rebuke during a wide-ranging interview published Monday night.
He said socialist policies are “seductive” and “easy” for politicians to campaign on, but warned about what would happen if they are put in place.
“You always have to be very careful, because socialism is easy to campaign on but tough to govern on, because the country goes down the tubes,” Trump told conservative website Breitbart.
“But when you tell people free medical, free education, no more student loans—all of the different things that you say—it’s a great thing to campaign on, but then ten years later the country is down the tubes. It’s gone.
“So, you always have to be careful with it, because you know you talk about single-payer, it sounds very seductive—single-payer—say what you want, but it’s a very seductive thing. But it means you’re not going to have good healthcare, it means the country is not going to be able to afford it.”
The president then suggested the 2020 election could come down to a “referendum on socialism versus capitalism,” according to the website.
Trump’s remarks come shortly after Vice President Pence accused Democrats of openly advocating for socialism with far-left policies such as "Medicare-for-all" and the Green New Deal -- a system he said had “impoverished millions of people around the world.”
Speaking at the Conservative Political Action Conference earlier this month, Pence said: “Under the guise of Medicare-for-all and a Green New Deal, Democrats are embracing the same tired economic theories that have impoverished nations and stifled the liberties of millions over the past century.
“That system is socialism.”
He pointed in particular to the Democratic 2020 presidential candidates, many of whom have backed the Green New Deal and Medicare-for-all in some form, and accused them of having “papered over the failed policies of socialism with bumper-sticker slogans and slick social media campaigns.”
The recent rise and dominance of a hard-left faction in the Democratic Party has opened the door for conservatives to again sound those warnings -- especially as figures such as Sen. Bernie Sanders, I-Vt., and Rep. Alexandria Ocasio-Cortez, D-N.Y., have openly embraced the label of “democratic socialism."
The Green New Deal would seek to eliminate fossil fuels in favor of 100 percent renewable energy, as well as overhaul America’s economy with universal health care, job guarantee programs and other costly items. Meanwhile, a number have called for Medicare-for-all plans, with both Sens. Kamala Harris, D-Calif., and Sanders not backing away from the idea that their proposals would eliminate private insurance.
Fox News' Adam Shaw contributed to this report.