China's foreign minister has hit out at the "extreme selfishness" of tariffs, hinting at the steep levies imposed on Beijing by US President Donald Trump.

"Certain countries" resort to "pressure and coercion, and trigger unjustified trade wars... This extreme selfishness only harms their credibility," top diplomat Wang Yi told his Uzbek counterpart Bakhtiyor Saidov, according to a ministry statement released on Saturday.

This will "only undermine their credibility", added Wang, who was speaking on Friday on the sidelines of a foreign ministers' meeting in Almaty, Kazakhstan.

China and the United States, the world's two biggest economies, are locked in an escalating tit-for-tat trade battle triggered by Trump's levies on Chinese goods, which have reached 145 percent on many products.

Beijing has responded with 125 percent tariffs of its own on US goods.