Copper and other base metals prices fell sharply on Friday as a threat by US President Donald Trump to impose new tariffs on China and bleak economic data added to pessimism over the demand outlook.

Benchmark copper on the London Metal Exchange (LME) was down 1.6% at $5,108 a tonne at 1640 GMT and on track for a weekly loss of 0.7%.

The Shanghai Futures Exchange (ShFE) was closed for a public holiday and will reopen on Wednesday. Some European countries were also holding public holidays.

Copper fell more than 40% from mid-January to mid-March, touching a four-year low of $4,371 as the coronavirus shuttered industry.

Analysts at Refinitiv cut their forecast for 2020 global copper mine output by 2.4% to 19.6 million tonnes. For a factbox on mine closures, click here:

ShFE lead stocks also fell by more than half, aluminium stocks slipped 22% and nickel inventories declined by 4%.

LME aluminium was down 0.5% at $1,487 a tonne, zinc fell 1.4% to $1,912.50, nickel slipped 2.1% to $11,935, lead lost 0.2% to $1,631.50 and tin was down 1.3% at $15,005. Aluminium and nickel were down this week, while zinc, lead and tin were on course for weekly gains.