The secretary general of the Organization of Petroleum Exporting Countries urged Gulf States to continue investing in oilfield development on Sunday, despite sharp falls in crude oil prices.

Abdullah Al-Badri told a forum in Dubai that OPEC has no target price for a barrel of oil. He said the investment will help prevent a shortfall in supply once demand picks up.

Al-Badri acknowledged the oil price has fallen further than market fundamentals should have dictated, Reuters reported.

The agency said the comments were his first since OPEC said it wouldn’t cut production levels to stem the collapse in oil prices at a meeting in Vienna on Nov. 27. OPEC re-committed to a production target of 30 million barrels a day.

The United States will continue to rely on Mideast petroleum despite rising domestic shale oil production, Al-Badri said.

Oil prices have shed nearly half their value since late June, including a 4% fall Friday that left benchmark U.S. oil prices at $57.81 a barrel — their lowest level since May 2009.

OPEC countries account for 40% of global oil production.

In its December report released Friday, the International Energy Agency said slowing demand for oil and more rapid growth in production point to more energy markets turmoil in 2015.

The report pushed U.S. benchmark oil futures to $57.81 a barrel and took stock prices with them. The Dow Jones industrial average fell 315 points, or 1.79%, to 17,280.83.

Benchmark crude oil prices plummeted in London last month following the OPEC meeting, with Brent crude sinking 6.2% to $69.11 a barrel. In June, prices were as high as $115 a barrel.