Bringing together his counterparts from the largely Sunni nations of Jordan, Saudi Arabia and the United Arab Emirates, Kerry pressed home "that the threat of ISIL is not just to Iraq, it's to the region," a senior State Department official said.
The top US diplomat also briefed them on his visit this week to Baghdad and Arbil, in northern Iraq, where he sought to persuade fractious Iraqi leaders to unify to save the country which risks tearing apart in the face of the militant threat.
Militants from the Islamic State of Iraq and the Levant this week seized the main border crossing from Iraq into Jordan, causing alarm in the Hashemite kingdom.
The oil-rich Sunni Gulf kingdom of Saudi Arabia has accused Iraq's Shiite Prime Minister Nuri al-Maliki of fuelling the crisis by marginalising the country's Sunni Arab minority.
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Washington has been calling on the countries to use their influence with Iraqi leaders and Sunni tribes to try to press for unity, as well as to disrupt any private networks which may be acting inside their own countries helping or funding ISIL.
The US Secretary of State will fly to Saudi Arabia tomorrow to discuss the turmoil in the Middle East with King Abdullah.
The Saudi monarch Abdullah today instructed authorities in the oil-rich kingdom to take "necessary measures" to defend the country from jihadists battling the government in neighbouring Iraq.
The measures were not spelled out but decided during a security cabinet meeting chaired by the king and devoted to discussing developments in Iraq and their impact on Gulf Arab monarchies.