President Donald Trump threatened additional tariffs against Canada and Mexico late Thursday, in his latest move to raise trade tensions with U.S. allies.

In a social-media post, Trump threatened 50% tariffs on Canadian-made planes sold in the U.S., and said he would decertify all aircraft made in Canada, in retaliation for Canada not yet certifying certain American-made Gulfstream jets.

"Canada is effectively prohibiting the sale of Gulfstream products in Canada through this very same certification process," Trump said on Truth Social. "If, for any reason, this situation is not immediately corrected, I am going to charge Canada a 50% Tariff on any and all Aircraft sold into the United States of America."

That would mainly affect Bombardier (CA:BBD.A) (CA:BBD.B), which largely makes regional and private jets.

Separately, in an executive order Thursday, Trump imposed unspecified tariffs against any country exporting oil to Cuba. The Trump administration has been pressuring Mexico to distance itself from Cuba, in an effort to weaken the Havana regime. On Tuesday, Mexico's President Claudia Sheinbaum said her government had paused some oil shipments to Cuba, but maintained it was an internal decision, not the result of U.S. pressure.

West Texas Intermediate crude prices (CL.1) retreated late Thursday, after global oil prices previously settled at a six-month high on concerns that the U.S. may soon launch military action against Iran.

Last year, Mexico passed Venezuela to become Cuba's largest supplier of oil, the Financial Times reported earlier this month.

That has left Cuba desperate for oil now that its next-biggest supplier, Venezuela, cut off its supply following a U.S. raid earlier this month that arrested President Nicolás Maduro and effectively seized control of Venezuela's oil industry for the U.S. On Tuesday, Trump told reporters that without Venezuela's aid, Cuba "will be falling pretty soon."

After a lull in the fall, Trump has been pushing tariff threats again in the new year. Last week he called off punitive tariffs against eight European allies who publicly opposed his desire to acquire Greenland, and over the weekend he threatened Canada with 100% tariffs if it makes a free-trade deal with China. Prime Minister Mark Carney said Sunday there are no plans for such a deal and explained that a recent trade agreement between Canada and China was merely to resolve some tariff quota issues.

And on Monday, Trump threatened South Korea with 25% tariffs, complaining that that country's legislature has been to slow to ratify a trade deal with the U.S. reached last year.