President Donald Trump is expected to introduce new 25% tariffs on Monday on all steel and aluminium imports into the U.S., on top of existing metals duties, in another major escalation of his shake-up of trade policy.

President Trump says he'll announce the U.S. will impose 25% tariffs on all steel and aluminum imports, including from Canada and Mexico, as well as other import duties.

The 25 percent tariff the president is proposing is almost identical to a move in his first term. Economists and foreign governments know what will come next.