FILE PHOTO: Iran's Oil Minister Bijan Zanganeh arrives for an OPEC meeting in Vienna, Austria, June 22, 2018. REUTERS/Heinz-Peter Bader/File Photo

GENEVA (Reuters) - OPEC has problems with some oil producers, and the reasons for Qatar’s exit from the organization must be examined, Iranian Oil Minister Bijan Zanganeh said on Tuesday, according to the Islamic Republic News Agency (IRNA).

Qatar said on Monday it will quit OPEC to focus on gas in a swipe at Saudi Arabia, the de facto leader of the oil exporting group which is trying to show unity in tackling an oil price slide.

“Examining the reasons for Qatar’s exit from OPEC is a necessity,” Zanganeh said. He added, “OPEC has big problems from some oil producers which Qatar is not a part of.”

Zanganeh did not elaborate but he appeared to be noting that Qatar is not one of the problematic oil producers in OPEC.