The United Arab Emirates says it is leaving the Organization of the Petroleum Exporting Countries (OPEC) and OPEC+ as of Friday, as an unprecedented energy crisis triggered by the Iran war exposes disagreement among Gulf nations.

The U.A.E. has been a longtime member of OPEC — a cartel of leading oil-producing countries — first through its emirate of Abu Dhabi in 1967 and later when it became its own country in 1971. OPEC+ is an alliance with other oil-producing countries created in 2016.

The stunning loss of the U.A.E. could create disarray and weaken the ​group, which has usually sought to show a ​united front despite internal disagreements over a range of issues from geopolitics to production quotas.