* GRAPHIC-2019 asset returns: http://tmsnrt.rs/2jvdmXl (Adds analyst comment, updates prices, changes dateline from BEIJING)
LONDON, June 21 (Reuters) - Copper and other industrial metals drifted down on Friday as investors worried about uncertainties ahead of next week's G20 meeting and rising U.S.-Iran tensions.
Copper hit a near one-month peak on Thursday after the U.S. central bank signalled rate cuts. U.S. President Donald Trump approved military strikes against Iran on Friday before calling them off at the last minute, the New York Times reported.
"There's a feeling that central banks threw money into the system and markets reacted well yesterday, but now you have a sobering morning," said Oliver Nugent, analyst at Citigroup in London.
He said the market was more concerned that fresh negotiations about a U.S.-China trade deal at next week's G20 meeting might not go well.
"Everyone's got the G20 meeting in their sights right now, and holding a position ahead of that is what's dominating the market," he said.
"We've cautioned that in the event of a trade escalation, that the dollar would rally further, oil would be sold off and copper could hit $5,500 or even breach that."
Three-month copper on the London Metal Exchange was down 0.1% at $5,965 a tonne by 1058 GMT, retreating after crossing above the $6,000 mark. The metal had hit $6,027 on Thursday, the highest since May 21.
Copper is on course for a 2.4% gain in London this week, in what would be its biggest weekly increase since the week ended March 29. The metal has been partly buoyed by strike action at Chile's Codelco, the world's largest copper producer.
* ALUMINIUM PREMIUMS: Premiums for Japanese aluminium shipments for July to September were set at $108 per tonne, up 3% from the current quarter, as tighter supply in Asia outweighed fears over weakening demand.
* ALUMINIUM POSITION: LME aluminium "exhibits the largest net spec short of the complex on our estimate at 19% of open interest", Alastair Munro at broker Marex Spectron said in a note.
LME aluminium shed 0.5% to $1,772.50.
* CHINA ZINC STOCKS: Zinc inventories in warehouses monitored by the Shanghai Futures Exchange climbed 7.6% from last Friday to 86,046 tonnes, the exchange said.
* OTHER METALS: LME zinc slipped 1.3% to $2,435 a tonne, nickel retreated from a three-week top struck on Thursday, declining 0.7% to $12,205, lead edged up 0.1% to $1,904.50 and tin fell 0.3% to $19,125.
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(Additional reporting by Tom Daly in BEIJING; Editing by Dale Hudson)