World leaders meeting in Paris to form a broad coalition against Islamic State have agreed to provide military aid to Iraq to fight the extremist network.
International efforts to combat the Islamist militants, who have grabbed large swathes of territory in Syria and Iraq, have taken on an added urgency after the beheading of British aid worker David Haines and the threat to kill a second UK hostage.
The summit was spearheaded by French President Francois Hollande and Iraqi President Fuad Masum - bringing together 30 countries to co-ordinate a response to the IS threat.
The nations agreed to "support the Iraqi government by any means necessary - including military assistance".
French foreign minister Laurent Fabius said: "When you are facing a terrorist group as dangerous as this one, a certain number of measures have to be taken of a military nature, and these will vary according to the country."
Mr Hollande opened the summit, warning: "The terrorist threat is global and the response must be global. The cowardly murder of David Haines is a terrifying example of what is going on...There is no time to lose."
Some 930 French citizens or residents, including at least 60 women, are actively engaged in jihad in Iraq and Syria, or are planning to go there.
Mr Masum said there was a need for a "quick response" to the Islamist group which he said had "committed massacres and genocidal crimes".
Representatives of the six-nation Gulf Co-operation Council (Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates) and US Secretary of State John Kerry were also among the delegates at the conference.
However, Iran said it had rejected a request from the US to join the fight against IS because of Washington's "unclean intentions".
Ahead of the talks, the US said several countries in the Middle East had offered to join airstrikes against the militants, while Australia said it would send aircraft and personnel and France announced it would begin reconnaissance missions over Iraq.
British Prime Minister David Cameron, who is under pressure to act following the killing of Mr Haines, has given no indication over whether he would commit military forces to airstrikes.
Video footage of the British aid worker's death showed a knife-wielding militant who speaks with a British accent. The clip also included a threat to kill a second hostage, Alan Henning, who was a volunteer on an aid convoy.
It followed the beheadings of two American journalists James Foley and Steven Sotloff.
Mr Cameron vowed to "hunt down" the "monsters" who killed Mr Haines, and said the crime would "strengthen our resolve" to smash the extremist network which has seized swathes of Iraq and Syria.
