The Paris-based IEA left its demand growth forecast for 2019 unchanged from its last report in January at 1.4 million barrels per day.

"It is supported by lower prices and the start-up of petrochemical projects in China and the U.S. Slowing economic growth will, however, limit any upside," the agency said.

The IEA raised its estimate of growth in crude supply from outside the Organization of the Petroleum Exporting Countries to 1.8 million bpd in 2019, from 1.6 million bpd previously.