During a press conference on Monday evening, Trump once again mentioned the tariffs that will come into effect tomorrow.
There is no room left for Mexico or Canada, said Trump according to AFP.
The tariffs are ready. They will come into effect tomorrow, continued the President.
The leading stock indexes, which were already down, fell further.
Just before the stock market closed, the news came that Trump had signed a presidential decree to raise tariffs on Chinese goods from 10 percent to 20 percent.
At the close, the broad S&P500 index stood at minus 1.8 percent, the Dow Jones industrial index at minus 1.5 percent, and the tech-heavy Nasdaq composite index at minus 2.6 percent.
Monday's decline for the S&P500 is the largest in a single trading day since December, writes CNBC.
The American semiconductor company Nvidia, the world's second-highest valued listed company, plummeted 8.7 percent. During the day, it was announced that TSMC, the world's largest semiconductor manufacturer, will invest over 1,000 billion kronor in the USA over the next four years.
Monday's broad declines should be seen in the light of Friday's gains, when the S&P500 climbed 1.6 percent.
Earlier on Monday evening, Trump also announced that the USA will introduce import tariffs on agricultural products on April 2.
