The UN Security Council unanimously adopted a resolution Friday aimed at weakening Islamists in Iraq and Syria with measures to choke off funding and the flow of foreign fighters.

It represents the most wide-ranging response yet by the top United Nations body to the jihadists who now control large swaths of territory in both countries and have been accused of atrocities.

The British-drafted measure also placed six Islamist leaders -- from Kuwait, Saudi Arabia and other nations -- on the Al-Qaeda sanctions list, which provides for a travel ban and assets freeze.

The six include senior Al-Qaeda leaders who have provided financing to the Al-Nusra Front in Syria and Abu Mohammad al-Adnani, the spokesman for the Islamic State in Iraq and the Levant (ISIL), now renamed Islamic State (IS).

British Ambassador Mark Lyall Grant noted that the 15-member council had shown "strong unity" in adopting the resolution to address the IS and Al-Nusra threat.

"We have watched with horror their brutal actions -- attempts to wipe out entire communities on the basis of their religion or belief, indiscriminate killing, illegal and savage executions, deliberate targeting of civilians and appalling levels of sexual violence, especially against women and children," he said.

The resolution was endorsed by all 15 members of the council, including Russia, whose backing for Syrian President Bashar al-Assad partly stems from concerns that his downfall could lead to Islamists ruling Damascus.

The resolution demands that IS fighters in Iraq and Syria, rebels from the Al-Nusra Front in Syria and other Al-Qaeda-linked groups "disarm and disband with immediate effect."

It "calls on all member states to take national measures to suppress the flow of foreign terrorist fighters" to the extremist groups and threatens to slap sanctions on those involved in recruitment.

The measure also warns governments and entities that trade with the jihadists, who now control oil fields and other potentially cash-generating infrastructure, "could constitute financial support" that may lead to sanctions.

The crisis in Iraq has prompted the United States to launch air strikes and air-drop food and water to help tens of thousands of civilians fleeing the militants' advance in fear for their lives.

France has agreed to send weapons to shore up Kurdish forces fighting the Islamists and Pope Francis has urged the UN to do everything it can to stop attacks against Christian and other religious minorities who have taken flight.

"Stories that have emerged from ISIL's bloody wake are the stuff of nightmares," US Ambassador Samantha Power told the council.

"This is the new front of the terrorist threat, and one with a devastating human cost."

- Broader response -

Describing the jihadists as a threat to international peace and security, the council has placed the resolution under chapter VII of the UN charter, which means the measures could be enforced by military force or economic sanctions.

But Russian deputy ambassador Petr Iliichev stressed that the resolution "cannot be seen as approval of military action."

In the resolution, the council accuses the jihadists of a series of atrocities and warns that they may constitute crimes against humanity.

The council has previously adopted statements condemning the IS offensive but the resolution makes the first attempt at a broader response, two months after IS fighters seized control of the main northern city of Mosul.

IS proclaimed a caliphate extending from northern Syria to eastern Iraq in late June.

"This group needs to be defeated," said Iraqi Ambassador Mohamed Ali al-Hakim, who stressed the need for all countries to follow up on the resolution.

Syria's Ambassador Bashar Jaafari welcomed the measure, saying the regime in Damascus had repeatedly warned of the Islamist threat and asserting that the Assad government was a "necessary partner in the fight against terrorism."

The United Nations is also backing Iraq's prime minister-designate Haidar al-Abadi and his bid to form a broad-based government that officials hope will be able to confront the IS "terrorist army."

Jihadist advances in Iraq and Syria: key dates
Nicosia (AFP) Aug 15, 2014 - Below are key developments regarding the spread of ultra-radical jihadists who control large swathes of territory straddling Syria and Iraq, where they are accused of perpetrating atrocities.

The UN Security Council on Friday unanimously adopted a resolution aimed at weakening the jihadists in the two Arab countries.

--2013--

- April 9: The leader of Al-Qaeda's front group in Iraq, Abu Bakr al-Baghdadi, announces a merger between his Islamic State of Iraq (ISI) and Al-Nusra Front, a jihadist group fighting Syrian President Bashar al-Assad's regime, to form the Islamic State of Iraq and the Levant (ISIL).

A day later, Al-Nusra Front -- unknown before the revolt unleashed in March 2011 in Syria -- pledges allegiance to Al-Qaeda chief Ayman al-Zawahiri, but distances itself from claims it has merged with ISI.

- December 19: Amnesty International accuses ISIL in Syria of abducting, torturing and killing detainees at secret prisons in areas under its control.

--2014--

- January 2-4: Iraq loses control of Fallujah and parts of Ramadi in western Anbar province to ISIL fighters and members of hostile tribes.

- January 3: Three groups of Syrian rebels unite to kill and capture dozens of ISIL members, whom they accuse of worse abuses than the hated Syrian president. Some 6,000 are killed in the deadly clashes between ISIL and rebels, according to a monitoring group.

- January 14: ISIL takes its stronghold, the Syrian city of Raqa, after days of fierce fighting with rival rebels for the northern provincial capital.

It is later accused of a reign of terror in its strongholds like Raqa, where it imposes its own extreme interpretation of Islam, makes arrests and carries out beheadings and stonings.

- February 3: Al-Qaeda disavows ISIL. Zawahiri had already ordered the group in May 2013 to disband and return to Iraq and announced that the Al-Nusra Front was Al-Qaeda's official branch in Syria.

- June 9: In Iraq, start of a lightning offensive by hundreds of ISIL jihadists, backed by officers of executed dictator Saddam Hussein, Salafist groups and certain tribes. They go on to seize broad swathes of territory.

They also advance towards the autonomous Kurdish region in northern Iraq, driving out tens of thousands of members of Christian minorities and the Kurdish Yazidi sect from their towns.

- June 29: ISIL declares an "Islamic caliphate" extending from Aleppo in northern Syria to Diyala province northeast of Baghdad. Renaming itself the Islamic State, it declares its chief Baghdadi "caliph" and "leader for Muslims everywhere".

Most Islamist movements in Syria reject the announcement.

- August 8: US jets strike jihadist positions in northern Iraq, the first US military operation in the country since American troops withdrew in 2011. Washington has since carried out daily air strikes and announced arms deliveries to Kurdish forces, along with Paris.

- August 15: The UN Security Council unanimously adopts a resolution aimed at weakening the jihadists by cutting off funding and the flow of foreign fighters.