Why is Trump using tariffs?

 Trump says "tariff" is his favourite word and for decades he has argued that the US should use them to boost its economy.

He says tariffs will encourage US consumers to buy more American-made goods, increase the amount of tax raised and lead to huge levels of investment in the country.

Trump wants to reduce the gap between the value of goods the US buys from other countries and the value of those it sells to them. He argues that America has been taken advantage of by "cheaters" and "pillaged" by foreigners.

Trump has also made other demands alongside tariffs.

The first announced during his current presidential term targeted key US trading partners China, Mexico and Canada. He said he wanted them to do more to stop migrants and drugs reaching the US.