China's imposition of tariffs on a range of American imports including pork, fruit and nuts, targets part of US President Donald Trump's political base and is a step deeper into a trade war.

But the tariffs were relatively precise and not unexpected, and avoided targeting major commodities such as soybeans. The tariffs cover a small percentage - US$3 billion (S$3.9 billion) - of America's US$140.5 billion worth of agricultural goods exports in the last fiscal year, of which China accounted for about US$22 billion.