Reconnaissance planes at the ready, France's president said there was "no time to lose" in the global push to combat extremists from the Islamic State group, minus the two countries who share most of Iraq's borders.

With memories of the 2003 U.S. invasion of Iraq still fresh, the U.S. has so far been alone in carrying out airstrikes and no country has offered ground troops. But French reconnaissance jets were prepared to take off Monday, a French official said. An American official said several Arab countries had offered to conduct airstrikes. The officials spoke on condition of anonymity to discuss the sensitive issues.

"The terrorist threat is global and the response must be global," French President Francois Hollande said, opening an international conference Monday intended to come up with a global strategy against the group. "There is no time to lose."

Muslim-majority countries are considered vital to any operation to prevent the militants from gaining more territory in Iraq and Syria. Western officials have made clear they consider Syrian President Bashar Assad part of the problem, and U.S. officials opposed France's attempt to invite Iran.

France's foreign minister acknowledged that a number of the countries at the table Monday had "very probably" financed Islamic State's advances, and Iraq's president appeared ambivalent about Arab participation, saying his country needed the support of its neighbors — but not necessarily their fighter jets or soldiers.

"Ultimately, this is a fight within Islam, within Sunni Islam," White House chief of staff Denis McDonough told Fox News on Sunday.

The gathering itself was set to last just a few hours. French Foreign Minister Laurent Fabius said quick action was vital, insisting there was no comparison with the 2003 U.S. invasion of Iraq, which France vocally opposed.

"It's the same geographic area but that's the only similarity," Fabius told France Info radio on Monday. "When you are a political leader you have to measure the cost of inaction."

In an 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.

He also seemed lukewarm to the possible participation Egypt, the United Arab Emirates and Saudi Arabia in airstrikes 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 U.S. intelligence officials and private experts.

British Prime Minister David Cameron said his country would continue offering logistical help to U.S. forces and that counterterrorism efforts will increase, describing the Islamic State group as a "massive" security threat that cannot be ignored.