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.

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.

President Donald Trump is preparing to formally announce 25% tariffs on steel and aluminum imports. It's part of an aggressive effort to remake the existing terms of world trade that so far has compounded economic uncertainty.