OPEC, in its June report, said there were signs of deterioration in the global economy as the eurozone waivers on sovereign debt crises.
"These ongoing challenges to world economic recovery have led to even larger uncertainties for oil demand in the second half of this year," OPEC stated.
Nevertheless, the report stated there were signs the U.S. economy was showing more resiliency when compared with other developed economies.
Also crude oil inventories in the United States are "standing at the highest level since 1990," OPEC said. For production, OPEC said the United States is expected to average 9.66 million barrels per day in 2012.
"The current expected growth of U.S. supply is the highest since the 1970's," the report read.
World oil demand for 2012 is anticipated at 900,000 bpd, unchanged from the May report. Demand for OPEC crude is expected to average 29.9 million bpd, a minor revision from the previous assessment.
"The first half of this year experienced various economic developments world-wide, which placed a great amount of uncertainty on oil demand," OPEC cautioned. "The second half of the year is likely to experience an even greater degree of uncertainty."