— The military campaign against Islamist extremists in Syria and Iraq is inflicting heavy damage, said officials from a coalition working to uproot the militants from their self-declared caliphate.

Foreign ministers from the coalition of about 60 nations appeared so confident that they are making progress in the fight against the Islamic State that they have begun talking about the need to help Iraq rebuild once the extremists are ousted.

The issue was raised by Iraqi Prime Minister Haider al-Abadi at the Brussels meeting, which was held after a year-end NATO summit. No dollar figure was mentioned, however.

U.S. Secretary of State John F. Kerry said several nations in the region, both Sunni and Shiite, had offered to help pay for Iraq’s rebuilding once it is rid of the Islamic State, an al-Qaeda offshoot that is also variously known as ISIS, ISIL and Daesh.

“Might we have to contribute to it? Sure,” Kerry said, acknowledging some U.S. cost. “We ought to. It’s part of our foreign policy, and it’s part of our engagement.”

Iraqi soldiers hold the Iraqi national flag as they stand in front of a painted Islamic State flag in the town of Sa'adiya, northeast of Baghdad on November 24, 2014. (EPA)

But much of the cost, he added, will be paid by oil-rich countries of the Persian Gulf. Saudi Arabia, he said, had offered to donate $500 million. He added that several other countries, which he declined to name, also have indicated that they will help.

“We are particularly excited at the prospect of having the region engage in a significant way across sectarian lines, I might add, in order to be able to address this reconstruction notion,” Kerry said.

Kerry declined to discuss reports that Iran had launched airstrikes on Islamic State targets near its border, using U.S. warplanes purchased before the 1979 Iranian revolution. But he suggested that the attacks, if confirmed, would not be an unwelcome development. Although U.S. forces coordinate their strikes in Iraq with the Baghdad government, Kerry insisted that the United States and Iran are not coordinating attacks, or even considering doing so.

“I think it’s self-evident that if Iran is taking on ISIL in some particular place and it’s confined to taking on ISIL and it has an impact, it’s going to be — the net effect is positive,” he said. “But that’s not something that we’re coordinating. The Iraqis have the overall responsibility for their own ground and air operations, and what they choose to do is up to them.”

The ministers at the meeting were both optimistic and restrained as they assessed the coalition’s progress. In a joint statement issued at the close of their meeting, they said that the Islamic State’s advances are being halted and that airstrikes on the militant group’s strongholds have helped Iraqi and Kurdish troops reclaim territory.

But they cautioned that the Islamic State is far from defeated, despite some battlefield victories against the group since the U.S.-led coalition began a campaign of targeted airstrikes in the fall. In a short speech at the outset, Kerry reflected on both the gains and the long slog ahead.

“Our commitment will be measured most likely in years, but our efforts are already having a significant impact,” he said. He cited a series of strategic successes, including regained ground around dams and oil refineries in Iraq and airstrikes in Syria targeting the leadership of the Islamic State.

“It is much harder now than when we started for Daesh to assemble forces in strength, to travel in convoys and to launch concerted attacks,” he added. “No large Daesh unit can move forward aggressively without worrying about what will come down on it from the skies.”

Although several of the nations represented at the meeting are straining under the weight of sheltering some of the 13.6 million Iraqis and Syrians displaced by conflict, the gathering was infused with optimism about progress in the battle against the Islamic State.

In one measure of that confidence, the officials started talking about the long-range need to mend societies riddled with social ills that have allowed Islamist extremism to flourish.

“There is a growing sentiment . . . that ISIL is simply symbolic,” said a senior State Department official present at the meeting who spoke on the condition of anonymity to discuss the deliberations. “ISIL is representative of a larger issue, of a larger problem. There are deep social, economic, governance and educational issues which have, in many ways, created the environment in which radicalism and extremism can take root and ultimately gain coherence in these groups.”

Combating the Islamic State is akin to an emergency, he added. Down the road, the coalition expects to take a broader look at the conditions that served as a hothouse for a group whose brutality has been characterized by U.N. investigators as war crimes.

The Islamic State, nevertheless, has continued to expand its influence across the Middle East and North Africa. Army Gen. David M. Rodriguez, who heads the U.S. Africa Command, told Pentagon reporters Wednesday that the U.S. military is now tracking militant training camps in eastern Libya affiliated with the group. Rodriguez described the camps as part of a “very nascent” attempt by some extremists in Libya to align themselves with the powerful, well-funded Islamic State.

In Brussels, the ministers also made a thinly veiled reference to Syria’s future without President Bashar al-Assad. Their joint statement declared support for a political transition based on the principles of the Geneva communique, a 2012 document that says a transitional governing body could include members of the present government as well as opposition parties.

Missy Ryan in Washington contributed to this report.