In the wake of US President Donald Trump's latest tariff blitz on dozens of economies, China has reiterated a stern warning against protectionism amid growing concern that it will "harm the interests of all parties".

U.S. and Chinese officials agreed to seek an extension of their 90-day tariff truce on Tuesday, following two days of what both sides described as constructive talks in Stockholm aimed at defusing an escalating trade war between the world's two biggest economies that threatens global growth.