Copper prices rose on Wednesday, with the London contract hitting a more than two-year high, underpinned by falling output and a weaker U.S. dollar.

Three-month copper on the London Metal Exchange jumped as much as 1.8% to $6,686 a tonne, its highest since June 2018, while the most-traded September copper contract on the Shanghai Futures Exchange advanced 2.3% to 52,220 yuan ($7,544.61) a tonne.

China's refined copper output in July fell 5.3% from the previous month to 814,000 tonnes, official data showed, as smelters carried out summer maintenance and coronavirus-related mining curbs tightened concentrate supply.

However, January-July output advanced 3.9% year-on-year to 5.63 million tonnes, the data showed.

Meanwhile, the U.S. dollar struggled to recoup heavy overnight losses on Wednesday after it slipped to a 27-month low in the previous session on uncertainties about an economic recovery and the U.S. fiscal stimulus package.

A weaker U.S. dollar makes greenback-priced LME metals cheaper for holders of other currencies.