The U.S.-China trade war has already almost halved oil demand growth and things are only going to get worse, according to Citigroup Inc.

The conflict has cut 800,000 barrels a day from consumption growth since the end of March 2018, said Ed Morse, global head of commodity research at Citi, who sees demand expanding 940,000 barrels a day this year. Another 300,000 barrels will be lost if the dispute continues for six more months, he said on the sidelines of the Asia Pacific Petroleum Conference in Singapore.

“The argument about demand growth going down to 600,000 to 700,000 barrels a day is plausible,” Morse said in an interview. “An all-out trade war will be very challenging to the Chinese economy even with fiscal and monetary incentives” and economic growth could drop into the mid-5% range, he said.

Citi’s demand growth forecast is slightly more pessimistic than the International Energy Agency, which sees an expansion of 1 million barrels a day this year. UBS AG is projecting 900,000 barrels a day for this year and next.

Morse re-iterated his Brent crude price forecasts from earlier this month. He sees the global benchmark rising to $64 a barrel in the fourth quarter before plunging to $53 by the end of 2020. Brent is currently trading at about $63 a barrel.