Trump announces tariffs on Mexico until 'immigration remedied'

US to place 5% tariff on goods as Mexico president says 'social problems aren't resolved with taxes'

Donald Trump has announced that he is placing a 5% tariff on all Mexican imports to pressure the country to do more to curb immigration into the US, in a surprise move that has rattled markets.

The US president said the tariff would gradually increase "until the illegal immigration problem is remedied". He made the announcement via Twitter after telling reporters earlier on Thursday he was planning "a major statement" that would be his "biggest" so far about the border.

Related: Markets shaken as Trump announces shock Mexico tariffs - business live

Tariffs are border taxes charged on foreign imports. Importers pay them upon entry to the customs agency of the country or bloc imposing them.