Base metals prices have hit multi-month lows on Friday as the threat of a global trade war escalated after US President Donald Trump announced tariffs on up to $US60 billion ($A77.8 billion) of Chinese goods.

Trump plans to impose the tariffs for what he says is misappropriation of US intellectual property, but only after a 30-day consultation period that starts once a list is published.

Increasing tensions have sent jitters through financial markets as investors see dire consequences if the world’s two largest economies start erecting trade barriers.

In London, copper, aluminium and zinc hit their weakest since mid-December, while in Shanghai, copper retreated towards levels not seen since mid-2017, but trimmed some of its losses towards the end of the Asian day.

‘We expect copper to continue to rise during the course of the year, reflecting the supply deficit, but obviously we’re watching what could develop into a trade war. If it does, it changes everything,’ said Nitesh Shah, commodity strategist at ETF Securities.

* COPPER: London Metal Exchange copper ended down 0.5 per cent at $US6,660 a tonne, having plumbed its weakest since mid-December at $US6,623.50. Prices extended falls from the previous session, breaking the 200-day moving average for the first time in around 18 months.

* CHINA: China’s commerce ministry said the country was planning measures against up to $US3 billion of US imports to balance US tariffs against Chinese steel and aluminium.

* NICKEL, ZINC: A sell-off in steel spilled into inputs nickel and zinc. Shanghai rebar tumbled near seven per cent, while LME nickel closed down 1.8 per cent at $US12,950, having hit its lowest since early February. Zinc ended up 0.5 per cent at $US3,217, having hit its lowest since mid-December.

* ALUMINIUM: LME aluminium ended down 1.2 per cent at $US2,050.50, having hit three-month lows after breaking below the 200-day moving average earlier this month.

* STEEL: Chinese steel traders fear a prolonged market downturn as prices skid to their lowest in years.

* SHANGHAI ALUMINIUM: Aluminium inventories in warehouses monitored by the Shanghai Futures Exchange rose on the week to a record high of 940,318 tonnes.

* SCRAP: China’s scrap metal imports fell by 38.5 per cent year on the year as the country enforced its clampdown on foreign waste.

* CONGO: Democratic Republic of Congo’s mines minister rejected a proposal by mining companies on Friday to soften some provisions in a new mining code in exchange for higher royalties.

* OTHER METALS: Lead closed down 1.1 per cent at $US2,341 while tin ended down 0.5 per cent at $US20,750.