Kerry discusses ISIS strategies at Paris summit

Nearly 40 countries, including 10 Arab states, have signed up to a coalition to help fight ISIS.

US Secretary of State John Kerry. Picture: AFP.

LONDON - Foreign ministers from around the world are meeting United States Secretary of State John Kerry in Paris to discuss how to defeat Islamic state militants.

Nearly 40 countries, including 10 Arab states, have signed up to a coalition to help fight ISIS. The meeting is being held after a third hostage, a British aid worker was beheaded.

Kerry arrives at the summit after a whirlwind tour in the Middle East to garner support for a plan of action unveiled by US President Barack Obama last week.

The American strategy to weaken the group centres on military support for Iraq but also aims to stop foreign fighters joining the group, cutting its sources of funding and trying to counter its ideology.

The Paris conference is aimed at defining the role each member state will play in the fight to destroy ISIS.

Earlier, France announced it has joined the United Kingdom in conducting surveillance flights.

The summit has added urgency following the murder of British hostage David Haines by ISIS militants who then threatened to behead another British hostage over the coming days.

Obama on Saturday strongly condemned "the barbaric murder" of Haines by Islamic State militants after the group released a video purporting to show the beheading of the aid worker.

"The United States stands shoulder to shoulder tonight with our close friend and ally in grief and resolve," Obama said in a statement.

"We will work with the United Kingdom and a broad coalition of nations from the region and around the world to bring the perpetrators of this outrageous act to justice and to degrade and destroy this threat to the people of our countries, the region and the world."

Britain's Prime Minister David Cameron says the UK will help destroy ISIS and extinguish what he calls a terrorist threat to the global community.

Citizen could have carried out the killings.

Speaking after chairing a meeting of the government's emergency response committee in London, Cameron called the killing of Haines, a 44 year-old Scottish aid worker, callous and brutal and hailed him as a "British hero."

"We will hunt down those responsible and bring them to justice no matter how long it takes," he said, calling ISIS "the embodiment of evil" and saying his government was prepared "to take whatever steps are necessary" against the militants.

Kerry has been touring the Middle East to try to secure backing for US efforts to build a coalition to fight the Islamic State militants who have grabbed territory in Syria and Iraq.

The US resumed air strikes in Iraq in August for the first time since the 2011 withdrawal of the last US troops fearful the militants would break the country up and use it as a base for attacks on the West.

The addition of Arab fighter jets would greatly strengthen the credibility of what is a risky and complicated campaign.

"We have countries in this region, countries outside of this region, in addition to the United States, all of whom are prepared to engage in military assistance, in actual strikes if that is what it requires," Kerry said.

"And we also have a growing number of people who are prepared to do all the other things," he said in remarks broadcast on Sunday on the CBS programme Face the Nation.

Offers of Arab air participation have been made both to US Central Command overseeing the American air campaign and to the Iraqi government, a senior State Department official said.

Australia became the first country to detail troop numbers and aircraft to fight the militants in Iraq. It said it would send a 600-strong force and eight fighter jets to the region but did not intend to operate in Syria.

Russia, at odds with the West over Ukraine, has said any air strikes in Syria would be an act of aggression without the consent of President Bashar al-Assad or an international mandate.

Additional reporting by Reuters