President Donald Trump speaks during a working lunch with governors in the Roosevelt Room of the White House, in Washington, DC, on June 21, 2018.

President Donald Trump will win his trade fight, CNBC's Jim Cramer said Friday, but investors should hope it happens quickly.

"Stocks are getting cheap because I genuinely believe we are going to win the trade war," Cramer said on "Squawk on the Street." "You just need it be done within the next three to six months because the world [economy] is slowing too quickly."

Cramer spoke before Trump tweeted another tariff threat, this time targeting imported autos from the European Union.

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This week, Trump also instructed the U.S. trade representative to identify $200 billion worth of Chinese goods for additional tariffs at a rate of 10 percent. That would be on top of the 25 percent tariff on up to $50 billion of Chinese products that the president unveiled last week. Those latter measures, announced on June 15, are set to start July 6.

The Trump administration put tariffs of 25 percent on steel imports and 10 percent on aluminum imports from Canada, Mexico and the European Union earlier this month.

There are many "false reports" that the administration will "let up" on its trade tactics, Cramer said. However, the "Mad Money" host expects Trump and his White House advisors "really believe they have China on the run."

"Why make a truce?" Cramer asked, saying the thesis in the White House seems to be, "'Why should we take our foot of the pedal? Why not just crush them.'"

On Tuesday, Cramer said he's not worried yet about the escalating trade conflict between the United States and China.

Cramer contended that Trump has the upper hand. "The president is saying, 'You know what guys [China] ... we got more staying power than you, particularly with your stock market collapse.'"