Donald Trump has repeatedly urged Xi Jinping to call him for discussions about a potential trade deal. But any off-ramp to the economic tensions will likely run through Vice Premier He Lifeng, who is Xi's Sino-American trade tsar.

Trump has long accused China of exploiting the US on trade, casting his tariffs as necessary to revive domestic manufacturing and reshore jobs back to the US. He also wants to use tariffs to finance tax cuts. Most economists remain sceptical Trump will achieve his aims.

Economic risks are growing as the two sides appear to disagree about whether they are even engaged in tariff negotiations.