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.

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.

President Trump said Monday evening from the White House that he is aiming to place 25% tariffs on imports from Canada and Mexico on Feb. 1. Trump made the comment even as he plans to direct federal agencies to analyze federal trade practices and policies with China and North American allies.