OPEC had hoped to achieve market rebalance with the production cut which came into effect earlier, in January this year.
But the IEA cut estimates for the amount of crude needed from OPEC this year and in 2018 after lowering its historical assessments of consumption in some emerging nations.
The agency lowered projections for the amount of crude required from OPEC this year and next by about 400,000 barrels a day.
About 32.6 million barrels a day will be needed from the group this year, less than the 32.84 million it pumped in July, the IEA said.
Oil prices have lost about 9 percent in London this year on concern that supply curbs by OPEC and partners including Russia aren’t aggressive enough to clear a global surplus.
There are also growing doubts that all the countries involved in the accord to reduce supply are fully committed, the IEA stated.
OPEC’s rate of compliance with the cutbacks slipped last month to 75 percent, the lowest since the accord started in January.
Iraq’s implementation was just 34 percent, Venezuela’s 28 percent and the UAE’s 53 percent.
Adherence among the non-members coordinating with OPEC was at 67 percent.
OPEC Secretary General, Dr. Mohammed Barkindo, said late in July that rebalancing of the oil market will speed up in the second half of the year.
Barkindo, in Russia, said although rebalancing of the oil market is progressing slower than expected, the situation would improve in the second half.