Saudi Arabia's intelligence chief, Prince Bandar Bin Sultan al-Saud, has reportedly told European diplomats that his country plans to scale-back its cooperation with the US in efforts to arm and train Syrian rebels, according to the Wall Street Journal.
The decision was said to be the result of Riyadh's "frustration" with the Obama administration's foreign policy in the Middle East, and reflects a growing sense of discontent by one of America's staunchest Arab allies.
It comes days after the Gulf Kingdom surprised observers by turning down a temporary position on the United Nations Security Council, in what it said was a protest at the Security Council's ineffectiveness in solving regional conflicts.
But US diplomats told the WST that the real message was meant for the Obama administration, and not the UN as an institution.
“This was a message for the US, not the UN” Prince Bandar reportedly told diplomats privately, following the shock decision.
Saudi Arabia's King Abdullah has been described as particularly "angry" over the US's handling of the August 21 chemical weapons attack in Damascus, which was widely believed to have been carried out by the Assad regime.
Saudi officials were dismayed by the US decision not to strike the regime in response, after an apparently clear violation of President Obama's own "red line" over the use of chemical weapons.
But it has also been revealed that two, previously undisclosed incidents between the two countries contributed to a significant deterioration in the relationship, according to "diplomats and officials familiar with events".
First, American officials surprised their Saudi counterparts by refusing to guarantee the security of Saudi Arabia's vital oil regions in the event of military intervention in Syria, despite the real threat of retaliation against the Saudis by the Assad regime. Saudi officials apparently responded by warning US diplomats that they would consider pursuing alternatives to the mutual defense pact between the two countries, and that they could obtain cheap weapons elsewhere.
The second incident occurred after the Saudi government expressed its will to aid the US in striking Syria, and to that end requested a list of potential targets. In what was taken as a snub in Riyadh, the Americans never responded.
Saudi Arabia is also said to be concerned about American overtures to its arch-foe, Iran, and alarmed at what they see as an incoherent and weak American Middle East strategy.
“The Saudis are very upset. They don’t know where the Americans want to go,” WST quoted a "senior European diplomat" as saying.
But White House National Security Council spokeswoman Bernadette Meehan denied that relations between the two countries were anything but strong.
“The United States and the Kingdom of Saudi Arabia have a long-standing partnership and consult closely on issues of mutual interest, including preventing the proliferation of weapons of mass destruction, countering terrorism, ensuring stable and reliable energy supplies, and promoting regional security,” she said.
“While we do not agree on every issue, when we have different perspectives we have honest and open discussions,” said another, unnamed, senior administration official.
Saudi Arabia has invested hugely in the Syrian rebel movement - viewing the defeat of the Iranian-backed Syrian regime as of paramount importance to forestalling Iranian regional dominance - and the kingdom is not taking any prisoners in trying to secure an outcome that is favorable to its interests.
Recent reports suggested that an upcoming major military offensive by pro-regime forces against a key rebel stronghold prompted Saudi Arabia to issue a veiled threat to Iran's proxy, Hezbollah.
A Lebanese politician told journalists that the Saudi government had warned Hezbollah that it would incur a cost for any involvement in a potential setback for the rebel movement in the Qalamoun region.