Representatives from the US and China are meeting in Washington this week to resume trade talks after a recent series of tit-for-tat tariffs were announced by both countries.

Reuters reported Chinese fabricators were rushing to buy copper before additional tariffs, announced two weeks ago on US$16 billion worth of US imports including scrap metal, came into force today.

Coal traders had also started sourcing supplies domestically, the wire service reported.

"We have completely stopped US metallurgical coal (imports), which is popular among steel mills, in late July," a senior manager with coal trading house Shanghai Runhei International told Reuters.

"There is too much uncertainty in trade."

US National Association of Manufacturers president and CEO Jay Timmons said they were encouraged the US had "succeeded in getting China back to the table for negotiations".

The copper spot price has tumbled as US-China trade tensions ratcheted up, from a 52-week high of US$7,330/t on the London Metal Exchange on June 8 to close yesterday at $5,980/t.