The bloc of monarchies was created in 1981 to coordinate political and economic policies.
Following a meeting Tuesday in Riyadh, Gulf Arab leaders welcomed Jordan’s request to join. A statement on the Jordanian news agency said King Abdullah II conducted “intensive efforts” with the GCC.
The six countries are seen as among the most influential of the Organization of the Petroleum Exporting Countries’ members. They have relied on their oil wealth to secure political and economic clout.
Last month the GCC sent troops into Bahrain, which is facing a rebellion against its monarchy.