Saudi Arabia, in an unprecedented show of anger at the failure of the international community to end the war in Syria and act on other Middle East issues, said on Friday it would not take up its seat on the United Nations Security Council.
The kingdom condemned what it called international double standards on the Middle East and demanded reforms in the Security Council, which has been at odds on ways to end the fighting in Syria.
Riyadh's frustration is mostly directed at Washington, its oldest international ally, which has pursued policies since the Arab Spring that Saudi rulers have bitterly opposed and which have severely damaged relations between the two, Saudi analysts have said.
Saudi Arabia has also been angered by a rapprochement between Washington and Iran, Riyadh's old regional foe, which has taken root since President Barack Obama spoke by telephone last month to the new Iranian President, Hassan Rouhani, in the highest-level contact between the two countries in more than three decades.
Citing the Security Council's failure to resolve the Israeli-Palestinian dispute, take steps to end Syria's civil war and stop nuclear proliferation in the region, Riyadh said the body had instead perpetuated conflicts and grievances.
"Saudi Arabia ... is refraining from taking membership of the U.N. Security Council until it has reformed so it can effectively and practically perform its duties and discharge its responsibilities in maintaining international security and peace," said a Foreign Ministry statement.
A decision of such magnitude would have to have been taken by King Abdullah or Crown Prince Salman, said a Saudi analyst who asked not to be named.
"Saudi Arabia has been working on (getting onto the Security Council) for the last three years. They trained diplomats, male and female, the cream of the Foreign Ministry, our best talented youths. Then somebody made the decision suddenly to pull out," he said.
The conservative Islamic kingdom has traditionally avoided big political statements, preferring to wield its influence as the world's top oil exporter, birthplace of Islam and chief Arab ally of the United States behind closed doors.
However, immersed in what they see as a pivotal struggle for the future of the Middle East with arch rival Iran, Saudi rulers are furious that the U.N. has taken no action over the Syrian conflict where they and Tehran back opposing sides.
Blood-drenched images of Syria's civil war, in which more than 100,000 have died and in which millions have been displaced, are aired daily on Saudi news.
Prince Saud has previously described President Bashar al-Assad's assault on areas held by rebels supported by Saudi Arabia as "genocide".
Saudi anger boiled over after Assad escaped U.S.-led military strikes in response to a poison gas attack in Damascus by agreeing to give up his chemical arsenal.
"There are people being killed every day, every hour. And the Muslim world is very angry because we don't see any action or any strong stance from the Security Council towards this situation," Abdullah al-Askar, chairman of the foreign affairs committee in the kingdom's quasi-parliament, the Shoura Council, told Reuters.
The Security Council has been split on how to handle the civil war in Syria, with Western powers pushing for stronger sanctions against Assad and Russia vetoing resolutions to that end. Saudi Arabia has backed the rebels in that conflict.
The Saudis, along with other Arab states, have also often criticised the United States for blocking international action to end the Israeli occupation of Palestinian lands seized in the 1967 Middle East war.
In an earlier sign of mounting Saudi anger, Foreign Minister Prince Saud al-Faisal two weeks ago cancelled his speech at the U.N. General Assembly in what a diplomatic source said was a response to international inaction on Middle East issues.
In the past, Saudi anger was usually reserved for Russia and China, permanent Security Council members that had blocked resolutions targeting Assad, but it now also extends to its main Western ally, Washington.
It has been sharply critical of U.S. policy in the Middle East since the Arab Spring, not only on Syria but also in Egypt, where Washington cut off aid to the military after it ousted a Muslim Brotherhood government that Riyadh saw as a threat.
In an interview with pan-Arab daily al-Hayat on Tuesday, Saudi Arabia's ambassador to the U.N. Abdullah al-Muallami described U.S. policy on Egypt as "arm-twisting".
Egypt's Foreign Minister said relations were in "turmoil" after Washington moved to curtail military aid to Cairo in a row over the way the army overthrew Islamist President Mohamed Mursi.
Saudi Arabia, a founding member of the U.N., was one of five countries elected by the body's General Assembly on Thursday to serve a two-year term on the 15-member U.N. Security Council.
The council, which has powers to authorise military action, impose sanctions and set up peacekeeping operations, has 10 rotating members. The U.S., China, Russia, France and Britain are permanent members which wield a veto.
Alongside its anger over inaction on Syria, Saudi Arabia also cited the proliferation of weapons of mass destruction and the failure to resolve the Palestinian crisis as reasons for declining its first ever seat on the Security Council.
The Saudis have said they were very disappointed at Obama's failure to push Israel to end settlement building in the West Bank and agree to a Palestinian state after he was elected in 2008.
They have previously pressed Washington to "cut off the head of the snake" by striking Iran's nuclear programme, which they and Western countries fear may be aimed at building an atomic bomb, according to diplomatic cables released by WikiLeaks.
Iran says its nuclear programme is entirely civilian.