Tariffs are possible on imports from Mexico, Canada and China. The president of a small Arizona business wonders if her firm could survive a trade war.

While Arizona Republicans praise President Donald Trump’s tariff threat against Mexico as a deft negotiating ploy, Democrats warn it is creating an increasingly unstable relationship with the state’s largest trading partner.

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".