Former US Secretary of Defense accuses Saudi Arabia of failing to fight ISIS

Carter, who led the Pentagon under former President Barack Obama in 2015-2017, said in an interview with CNN on Tuesday that the Saudis "have not proved to be reliable or competent military allies," adding that Trump himself has not shown the required competence in this area.

"It's good to be friends and allies, but oil is no longer what it used to be," he said, referring to relations between Washington and Riyadh.

He pointed out that Riyadh's acquisition of US weapons is not a service but an equal trade process and "the kingdom does not actually have any alternative option," he said.

Carter said that the Saudis "did not succeed" whenever asked by the US administration to do something as an ally, and touched in this regard on the negotiations that took place between him and Crown Prince Mohammed bin Salman on efforts to combat "ISIS".

"I asked him repeatedly about whether they would do anything against ISIS, but they didn't do anything about it, Instead, they once announced the formation of an alliance without telling anyone in the Muslim world that they were building an Islamic alliance." he added.

Carter generally praised the idea of forming an Islamic alliance against terrorism, but at the same time, pointing out that "the Saudis performance was not always at the same level as they were referring to."