Trump has also threatened to introduce tariffs - a tax on imports - on goods from Canada and Mexico, but paused these for 30 days after both countries agreed to boost border security. The US president has said tariffs are needed to help the American economy and to "protect" the country from the "major threat of illegal aliens and deadly drugs".

Canadian prime minster Justin Trudeau has promised to retaliate if US president Donald Trump imposes tariffs - Nicholas Kamm/AFP

President Trump on Monday paused the threat of 25-percent tariffs against Canada and Mexico, two of the nation’s biggest trading partners, and claimed an early victory in his mission to crack down on drug and human smuggling along the northern and southern borders.