Saudi Arabia's energy minister has spoken of the possibility of OPEC oil producers and their non-OPEC partners not reaching a deal over whether to cut oil production this week.

Asked how real the risk a "no deal" scenario at the meeting on Thursday, which comes amid another slump in oil prices, Saudi Energy Minister Khalid al-Falih told CNBC's Hadley Gamble: "It's real."

Oil prices dropped 4.7 percent Thursday after Al-Falih signaled that the 15-member oil producing group could cut less than expected. Al-Falih said earlier that a cut of 1 million barrels per day would be enough for OPEC and its allied oil producers. Markets had factored in a cut of around 1.2 million to 1.4 million barrels per day.

As OPEC's de-facto leader, Saudi Arabia is under pressure to take a lead on stabilizing oil markets but it looked somewhat isolated at the Thursday meeting with non-OPEC partner Russia looking reluctant to agree to a cut. Iran's oil minister also told CNBC that Iran, which is already laboring under U.S. sanctions, will not cut anything.