Trump is about to roll out his massive new tariffs - here's what we know about them

• President Donald Trump will announce his new tariffs on steel and aluminum at a White House event.
• The tariffs will reportedly kick in in 15 days.
• Canada and Mexico will be exempt and other countries can apply for exemptions.

---

President Donald Trump will roll out his new tariffs on steel and aluminum at a White House event Thursday, kicking off what some economists fear could be a new protectionist shift for the administration.

Republicans , US allies, economists, and investors have all raised concerns about the economic impact of the tariffs amid concern it could lead to a trade war.

Trump is imposing the tariffs on national security grounds using an obscure bit of trade law. The administration argues that the US steel industry's struggles could leave the country exposed if imports are cut off due to a geopolitical conflict.

The rollout has been rife with confusion and dissension in the White House. Details of the tariffs have been changing throughout the week, but here's what we know so far based on Trump's statements and reports :

• Steel imports will be hit with a 25% tariff, aluminum with a 10% tariff.
• The measure will kick in 15 days from Thursday - on March 23.
• Canada and Mexico will be exempt indefinitely. Both countries had warned of retaliatory measures if they were not exempt. So far, the Trump administration has loosely tied the exemptions to negotiations over the North American Free Trade Agreement and warned that a failure to renegotiate the agreement could end the special treatment.
• Other countries can be exempt if the nations present an alternative way to address the national security threat of their exports, according to the Associated Press .