Provoking trade disputes is "naked economic terrorism", Chinese Vice Foreign Minister Zhang Hanhui said on Thursday, amid a lengthening trade dispute between the world's top two economies.
Tit-for-tat tariffs between the two countries resumed earlier this month, the United States blacklisted China's Huawei Technologies and China hinted it may use its dominant position as an exporter of rare earths as leverage.
"Negotiations appear to have halted and although there has been nothing specific to suggest that there won't be further discussions, the recent actions from the Chinese indicate everything is moving in the wrong direction in terms of getting a deal," said Capital Economics analyst Ross Strachan.
The conflict has the potential to sap demand for copper from China, which accounts for nearly half of global consumption estimated at around 24 million tonnes this year.
Three-month copper on the London Metal Exchange slipped 0.6pc to $5,846 a tonne by 1000 GMT, its lowest since Jan. 4.
STOCKS: On-warrant stocks of copper available to the market rose 4,500 tonnes to 198,625 tonnes in LME-approved warehouses, having jumped about 70pc so far this year.
In China, stocks of copper fell to 172,266 tonnes, according to last available data from the exchange on Friday.
TIN: Prices for LME tin touched the lowest since November at $18,630 per tonne but later rebounded to trade 0.3pc higher at $18,775. Stocks of tin have shot up 60pc so far this week to 2,650 tonnes.
RARE EARTHS: The US Defense Department is seeking new federal funds to bolster domestic production of rare earth minerals and reduce dependence on China as media reports said Beijing was standing ready to use rare earths to strike back at Washington.
TRADE WAR: In a fight against US sanctions that threaten to push it out of global markets, Huawei Technologies filed a legal motion seeking to declare a US defence law unconstitutional.
CODELCO: The possibility of a strike at top copper producer Codelco's Chuquicamata mine increased after three unions at the mine rejected the company's final offer for a new contract on Wednesday and approved a strike. Government mediation to avert a strike is still an option.
PRICES: Aluminium fell to its lowest in a week, down 0.2pc to $1,791 per tonne, zinc was flat at $2,543, lead slipped 1.2pc to $1,812.50, and nickel eased for a third straight session, down 0.3pc at $12,015.