Copper prices hit their highest in more than two years, boosted by signs of robust demand from China, tight supplies, a weak US dollar and a break of key technical levels.

Benchmark copper on the London Metal Exchange ended up 3.3 per cent at $US6225 a tonne, having earlier touched $US6234.50 a tonne, its highest since May 2015. Gains accelerated after New York opened.

"China growth is looking stronger, it's encouraging at a time when you would normally expect a lull," said Cantor Fitzgerald analyst Asa Bridle. "We have a perfect combination of decent demand and tighter supplies."

Traders say talk of a Chinese ban on scrap containing copper based on this notification may have helped trigger copper's rally.

China's gross domestic product was up 6.9 per cent in the second quarter year-on-year, faster than the consensus 6.8 per cent and the government's 6.5 per cent target.

The US currency fell to a 13-month low against a basket of major currencies, making dollar-denominated metals cheaper for holders of other currencies and potentially helping demand.

Disruptions to copper shipments from Canada and Chile have undermined expectations for rising global copper supplies in the second half of the year.

A break of $US6030, a Fibonacci retracement, and the February high at $US6204 saw funds that trade using buy and sell levels from black-box models jump on the uptrend, traders said.

Resistance is now seen around $US6400, an area of congestion from May 2015 but traders say copper is overbought and needs to consolidate before trying to tackle higher levels.

"Manufacturers are restocking after drawing down copper stocks," a trader said. "There has been a fair amount of short-covering too ... Momentum seems to be running out of steam and we've seen some producer selling."

President Rodrigo Duterte said on Monday he wants all mineral resources extracted in the country to be processed domestically and, if possible, to stop exporting such commodities.

The Philippines is the world's top supplier of nickel ore, for which China is the biggest market.

Worries about supplies pushed benchmark nickel up to $US10,015 a tonne, its highest since April 11. The price ended up 2.3 per cent at $US10,010 a tonne.

Upside barrier at $US10,080 a tonne, the 200-day moving average. Support at $US9370 a tonne, the 21-day moving average.

Aluminium was up 0.9 per cent at $US1930 a tonne, zinc rose 1.7 per cent to $US2836 a tonne, lead added 2.6 per cent to $US2318 a tonne and tin gained 0.7 per cent to $US20,305 a tonne.