Mexico currently supplies around 70% of the U.S. tomato market, up from 30% two decades ago, according to the Florida Tomato Exchange.

The move comes as the Commerce Department officially withdrew from a longtime trade agreement governing imported tomatoes on Monday, July 14.The tariff is slightly lower than the 21% duty floated by Trump officials in April,

While Mexico was spared from Trump's so-called "Liberation Day" tariff rollout on April 2, the 30% rate for the E.U. is 10 percentage points higher than what the president said he would apply to America's largest trading partner in April but lower than his mid-May threat of 50%.

The tariffs are likely to inflame tensions with one of the largest U.S. trading partners.

President Donald Trump posted letters to the leaders of Mexico and the European Union, saying they had not done enough to head off the new tariffs.

On August 1, a significant shift in international trade is expected as President Donald Trump enacts a 30% tariff on imports from the European Union and Mexico, two of the U.S.'s largest trading partners.

The president has earned a reputation for bluffing on tariffs. But he has steadily and dramatically raised U.S. tariffs, transforming global trade.

Wall Street is pointing lower before the opening bell with new tariffs announced for Europe and Mexico and as the unofficial start of earnings season get under way this week. Futures for the S&P 500, Dow Jones Industrial Average and Nasdaq each retreated by about 0.3% early Monday.