Benchmark copper on the London Metal Exchange (LME) was up a touch at $5,834 a tonne by 0931 GMT, having earlier dropped to $5,801 a tonne, its lowest since Jan. 4.
"Pessimism has taken hold. A recovery will need an end, or at least conciliatory moves between the two sides," a fund manager trading metals said, referring to the US-China trade dispute.
"Manufacturing PMIs show the decline in activity, the outlook for industrial metals doens't look good."
Copper prices on the Shanghai Futures Exchange fell to a two-year low at 46,050 yuan.
HIT LIST: China on Friday threatened to unveil an unprecedented hit list of "unreliable" foreign businesses, groups and individuals that harm the interests of Chinese companies. It imposed additional levies on the majority of US imports on a $60 billion target list on Saturday.
"These actions could be viewed as putting China back onto a level playing field," ING analysts said in a note.
"The US should now know that suppressing China will result in bounce-back retaliation from China. Whether this will encourage the US to go back to the negotiation table is hard to gauge."
CHINA: Factory activity in China expanded at a modest pace in May, a private survey showed, but analysts say that front-loading of exports to the United States in an effort to avoid higher tariffs masked underlying weakness in the economy.
EURO ZONE: Manufacturing activity in the euro zone contracted for a fourth month in May and at a faster pace, a survey showed.
ISM: The Institute for Supply Management's survey of US manufacturing is due later on Monday. The headline index weakened considerably in April.
TREATMENT CHARGES: Treatment charges for copper on the spot market have fallen to 6-1/2 year lows and are expected to stay under pressure because of shortages of the concentrate used to make refined metal.
TECHNICALS: First support for copper is at $5,772.50, the low on Jan. 4. Strong support comes in at the 18-month low of $5,725 hit on Jan. 3.
POSITIONS: "The copper net speculative short position has inched up to 7.4% of open interest, or 13,000 lots, largely back to levels not seen since October," Marex Spectron analysts said in a note. One lot is 25 tonnes.
"Last year the short in copper peaked at 30pc of open interest on July 19."
PRICES: Aluminium slipped 0.3pc to $1,789 a tonne, zinc lost 1.9pc to $2,476, lead was down 0.3pc at $1,800, tin was little changed at $18,715 and nickel fell 0.8pc to $11,920.?Reuters