President Donald Trump on Tuesday warned that even more tariffs could be coming as soon as next week: This time China was his target, as Trump threatened to unleash a wave of higher taxes on imports from America’s second-biggest trading partner.

It follows threats by Trump to levy import taxes of 25% on Mexico and Canada, accusing them of allowing undocumented migrants and drugs into the US.

Trump underscored his intention to use tariffs, a tax on foreign goods, as a tool of international economic policy and an increasingly vital source of government revenue.