President Donald Trump in recent days slapped tariffs as high as 50% on dozens of countries, restoring the type of aggressive trade policy that sent stocks plummeting a few months ago. The new round of levies prompted little more than a shrug on Wall Street.

Mexican President Claudia Sheinbaum on Tuesday said Mexico will take action if an agreement with Washington regarding new tariffs is not reached by the August 1 deadline set by her U.S. counterpart Donald Trump.

The US is imposing a 17% tariff on most tomatoes imported from Mexico with immediate effect, the government said. The duty came into force after the US withdrew from a long-standing agreement with its southern neighbour, arguing that the deal "had failed to protect US tomato growers from unfairly priced Mexican imports".

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.

Plus, the Justice Department has subpoenaed 20 doctors and clinics involved in “performing transgender medical procedures on children.”

President Donald Trump said he would send letters to more than 150 countries notifying them of tariff rates as he pushes ahead with a trade agenda that has sent US partners racing to avoid higher import taxes.