Gulf Arab monarchies yesterday said they were ready to help counter advances by jihadists in Syria and Iraq, after the US called for a global coalition to fight the militants.
The foreign ministers of Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates -- the six GCC states -- also pledged a readiness to fight "terrorist ideology which is contrary to Islam".
But GCC said it was awaiting details from Washington and a visit to the region by US Secretary of State Department John Kerry to discuss anti-jihadist cooperation.
US President Barack Obama has said he was developing a broad plan that would involve military, diplomatic and regional efforts to defeat the IS jihadists who have sown terror through crucifixions and gruesome beheadings.
The declaration came as Saudi Arabia's King Abdullah warned that the West would be the group's next target unless there was swift action to stem their advances through Iraq and Syria.
Britain on Friday said it was raising its terror alert level to "severe," meaning an attack is "highly likely," though Washington said it had no plans to follow suit.
And in Syria, clashes broke out between Philippine UN peacekeepers and another jihadist group, the al-Qaeda-linked Al-Nusra Front.
On Wednesday, fighters from Al-Nusra seized the Syrian side of the Quneitra border crossing with the Israeli-occupied Golan Heights. They took hostage 44 Fijian UN peacekeepers and have surrounded a group of 72 other UN peacekeepers from the Philippines.
The UN later said that thirty-two Filipino peacekeepers had been evacuated after being caught up in heavy fighting while others remain under fire.
The Pilipino group was part of a 72-member contingent situated in two different locations in the area. Philippine Defence minister Voltaire Gazmin yesterday said that all troops were safe.
Writing in the New York Times, a week before a Nato summit in Wales, Kerry urged "a united response led by the United States and the broadest possible coalition of nations".
He said he and Defense Secretary Chuck Hagel would meet European counterparts on the sidelines of EU summit to enlist assistance, and then travel to the Middle East to build support "among the countries that are most directly threatened".
Obama has acknowledged that Washington has no strategy as yet to tackle the Islamic State, which has declared an Islamic "caliphate" in large swathes of territory under its control in Iraq and Syria.
But Kerry said in his op-ed Friday that the United States would be putting forward an action plan at a summit meeting of the UN Security Council in September, when Washington will hold the group's rotating presidency.
"What's needed to confront its nihilistic vision and genocidal agenda is a global coalition using political, humanitarian, economic, law enforcement and intelligence tools to support military force," Kerry said.
The Islamic State (IS) has prompted widespread concern as it advances in both Syria and Iraq, killing hundreds of people, including in gruesome beheadings and mass executions.
The United States began carrying out air strikes against the group in Iraq earlier this month, but has yet to decide if it will expand that military action into Syria.