If tariffs from the U.S. or China become a reality, the result would be "a serious trade war," Citigroup's chief economist, Willem Buiter, told CNBC on Wednesday.
"It would be the biggest self-inflicted wound since the great financial crisis," Buiter said on "Power Lunch." He added that, "It would be the end of the global recovery," with problems beginning in the and China, but eventually spilling over into Europe, Japan and other countries.
"It would be very disruptive, both for importers and exporters," Buiter said. "And it would be a major cyclical downturn, depending on how intense and how long-lasting this episode would be."
On Tuesday, President Donald Trump met with Japanese Prime Minister Shinzo Abe in Florida. Discussions included the Trans-Pacific Partnership, or TPP, a trade pact, and whether or not the U.S. would rejoin. Some experts say the TPP is one method for dealing with China's allegedly unfair trading practices.
Trump tweeted Tuesday evening that the partnership was not a good deal for the U.S., a move Buiter called "a step backwards."
But Buiter said the final U.S. role in the TPP will likely not be settled for a number of years.