Beijing: US Commerce Secretary Wilbur Ross left Beijing on Sunday with no word of a breakthrough that could avert a trade war between the world's two biggest economies.

Instead, China issued a public warning that any deal is off if US President Donald Trump makes good his threat to impose punitive tariffs on Chinese technology.

Trump has stunned US allies Canada, Mexico and the EU in recent days by imposing tariffs on their steel and aluminium, invoking swift threats of retaliatory measures against American jeans, bourbon and maple syrup, among many other products.

In the days prior to Ross' arrival in Beijing, Trump set a June 15 deadline for naming $US50 billion $66 billion) of Chinese products to be hit with a 25 per cent punitive tariff in another apparent attempt at trade brinksmanship.