Newly outraged by the beheading of yet another Western hostage, diplomats from around the world are in Paris pressing for a coherent global strategy to combat extremists from the Islamic State group - minus two of the main players and without any ground troops - in a conflict that threatens to spill beyond the Mideast.
US Secretary of State John Kerry has been pressuring allies ahead of a conference on Monday to show a united front, especially from majority-Muslim nations, saying nearly 40 countries agreed to contribute to a worldwide fight to defeat the militants before they gain more territory in Iraq and Syria.
The White House said Sunday it would find allies willing to send combat forces - something the United States has ruled out - but that it was too early to identify them. The US has so far been alone in carrying out airstrikes.
Several Arab countries offered to conduct airstrikes against the Islamic State group, according to a State Department official travelling with Kerry who briefed reporters on condition of anonymity to discuss diplomat developments during his trip.
A second official gave some examples of what the US would consider a military contribution: providing arms, any kind of training activity and airstrikes.
Muslim-majority countries are considered vital to any operation, although there have only been vague offers of help previously. Iran was struck off the invitation list, and Western officials have made clear they consider Syria's government part of the problem.
"Ultimately, this is a fight within Islam, within Sunni Islam," White House chief of staff Denis McDonough told Fox News on Sunday.
"That's why we know that ultimately to defeat and ultimately destroy ISIL, something that is not only in our interest but in the interest of the countries in the region, they are going to need to take the fight to it," he said, using one of the acronyms for the group.
"We'll build, we'll lead, we'll undergird, and we'll strengthen that coalition. But ultimately, they're going to help us beat them on the ground," McDonough said.
But the Paris conference, officially dedicated to peace and stability in Iraq, avoids mention of Syria, the power base of the militant organization gaining territory in both countries by the week. And the US opposed France's attempt to invite Iran, which shares a 1,400-kilometre (870-mile) border with Iraq. The gathering itself will be brief, a matter of a few hours between its start and a planned joint statement.
In an exclusive interview on Sunday with The Associated Press in Paris, Iraq's President Fouad Massoum - a Kurd, whose role in the government is largely ceremonial - expressed regret that Iran was not attending the conference.
Massoum noted "sensitivities between some countries and Iran."
He also seemed not to welcome the possible participation Egypt, the United Arab Emirates and Saudi Arabia in air strikes in Iraqi territory.
"It is not necessary that they participate in air strikes; what is important is that they participate in the decisions of this conference," he said, underscoring Baghdad's closeness to Iran and how tensions among the regional powers could complicate the process of forming a Sunni alliance.
Speaking in his first interview since becoming Iraqi prime minister, Haider al-Abadi told state-run al-Iraqiyya in comments aired Sunday that he had given approvals to France to use Iraqi airspace and said all such authorizations would have to come from Baghdad.
The killing of David Haines, a British aid worker held hostage by the militants, added urgency to the calls for a coherent strategy against the brutal and well-organized group, which is a magnet for Muslim extremists from all over the world and rakes in more than $3 million a day from oil smuggling, human trafficking, theft and extortion, according to US intelligence officials and private experts.
British Prime Minister David Cameron said his country would continue offering logistical help to US forces and that counterterrorism efforts will increase, describing the Islamic State group as a "massive" security threat that cannot be ignored.
"They are not Muslims, they are monsters," Cameron said.
Haines was the third Westerner to be killed by the extremists, after two American journalists. British officials also released the name of a second UK hostage being held by the group and threatened with death, identifying him as Alan Henning.
Following successes in Syria, fighters with the Islamic State group - among them many Iraqis - took on the Iraqi military in Sunni-majority Anbar province, capitalizing on long-standing grievances against the Shiite-led government in Baghdad.
When the militants arrived in Mosul, Iraq's second-largest city, the US-trained military crumbled almost instantly. Commanders disappeared. Pleas for more ammunition went unanswered. Troops ran from post to post, only to find them already taken by gunmen. In some cases, they stripped off their uniforms.
The militants seized tanks, missile launchers and ammunition that allowed their lightning advance across northern Iraq.
The CIA estimates the Sunni militant group has access to between 20,000 and 31,000 fighters in Iraq and Syria. A senior Iraqi intelligence official told The Associated Press that more than 27,600 Islamic State fighters are believed to be operating in Iraq alone, including about 2,600 foreigners. He spoke anonymously as he is not entitled to brief the media.
McDonough said Iraq's newly inclusive Iraqi government allowed the US and other countries to step up their role.
Australian Prime Minister Tony Abbott said he was preparing to contribute up to 10 military aircraft and 600 personnel to be deployed to the United Arab Emirates. A statement from his office said special operations personnel who could assist Iraq's security forces were being prepared also, but combat troops were not being deployed. Australia was not on the list of countries attending the Paris conference released Sunday by the French presidency.
German foreign minister Frank-Walter Steinmeier called Sunday for "internationally agreed action to effectively stop the flow of fighters and money."
Germany on Friday banned all activity on behalf of the Islamic State group, including the distribution of propaganda and the display of its symbols, and is supplying Kurdish forces fighting the extremists in Iraq with assault rifles, anti-tank weapons and armoured vehicles. But Germany has ruled out airstrikes and ground troops.
French President Francois Hollande and his Iraqi counterpart will co-chair the conference of 26 countries, plus the European Union, United Nations, and the Arab League. Hollande said the goals are to provide political support to the Iraqi government, coordinate humanitarian aid, and fight the Islamic State militants.
The conference agenda deliberately focused on Iraq for fear that discussions on Syria could distract from efforts to build a coalition. France had initially wanted to invite Iran, but US and Saudi officials objected.
"Political feuds and differences between Iran from one side and the West and Saudi Arabia should be set aside," said Hadi Jalo, a Baghdad-based political analyst. "Iran should be invited because whether we like or not, Iran is a key player in the region."
Unlike the US, France is stopping short of possible action in Syria although the Paris government has not ruled out airstrikes in Iraq. The French fear that airstrikes on extremists within Syria could strengthen President Bashar Assad's hand and raise international legal problems.