Copper prices fell slightly on Thursday as the dollar strengthened and stocks in Asian warehouses registered with the London Metal Exchange continued to rise in preparation for a 50% import tariff by the United States.

Three-month copper prices at the LME fell by 0.2% to $9,620.5 per metric ton during trade at the official auction, as they continued to fall from the three-month high of $10,020 per ton set in early July.

Some of the copper originally planned for the United States is returning to the LME system after Washington announced last week that it would impose a 50% import tariff on copper starting on 1 August. According to analysts at broker Sucden Financial, “LME copper stocks continue to climb, the equipment being re-routed to the stock exchange, the shipping window to meet COMEX tariff deadlines closing rapidly.” Copper stocks available or under LME warranty have increased by 70% to 110,950 tons since Washington announced its copper pricing plan, the highest since April 30, which allayed concerns about the availability of the metal for local supply

Aluminum fell 0.7% to $2,560.5, zinc and lead lost 0.2% to $2,706 and $1,973, respectively, while nickel slid 0.4% to $14,960.