Nobel Prize-winning economist Robert Shiller on Monday said that President Trump Donald John TrumpBiden on Trump's refusal to commit to peaceful transfer of power: 'What country are we in?' Romney: 'Unthinkable and unacceptable' to not commit to peaceful transition of power Two Louisville police officers shot amid Breonna Taylor grand jury protests MORE's tariffs on foreign nations are "not a sustainable policy."

“They are generating so much anger around the world," Shiller said on CNBC's "Power Lunch." "It’s not a sustainable policy.”

ADVERTISEMENT

Shiller, who won the Nobel Prize for economics in 2013, added that Trump's tariffs likely won't stick because they are "too crazy."

Shiller's comments come as trade tensions between the U.S. and foreign nations continue to intensify.

In recent weeks, Trump has imposed tariffs against Canada, Mexico and other U.S. allies, as well as China. Many of those nations have threatened they will respond with retaliatory tariffs.

On Sunday, The Wall Street Journal reported that Trump is also planning on barring multiple Chinese companies from making investments on U.S. technology. That report came about a week after Trump reportedly asked the U.S. trade representative to find $200 billion worth of Chinese imports for tariffs.

China has responded to Trump's tariff announcements by calling on countries to take “joint actions” against the U.S.

But Shiller also notes that Trump's antagonism towards members of the Group of Seven nations is not positive for the market.

“People believe that he’s good for the market," he said. "But not necessarily if we start antagonizing ... This kind of antagonism with our allies I think will eventually harm confidence.”

Shiller has been critical of Trump's approach to trade before.

In March, he said Trump's proposal for massive tariffs on steel and aluminum imports would launch the U.S. into a global crisis, calling the move similar to the “first shot in a war."

"I'd wonder if this isn't just a first step, that Trump has in mind raising other tariffs. Even if he doesn't there will be other countries who will retaliate and they'll get bigger. This is really like a first shot in a war and that's what is worrisome," Shiller told CNBC.