PARIS – The U.S.-led military coalition’s fight against the Islamic State militant group entered a new phase on Wednesday, with defense ministers from the seven countries most heavily involved in the operation pledging to continue fighting and look for ways to more aggressively target the group.

The United States, France, Germany, Britain, Italy, Australia and the Netherlands made the promise here after a joint meeting hosted by U.S. Defense Secretary Ashton B. Carter and his French counterpart, Defense Minister Jean-Yves Le Drian. The group’s members said in a joint statement that they have “expressed our broad support for the campaign plan objectives, and the need to continue gathering momentum in our campaign.”

Navy Vice Adm. Mark I. Fox, the deputy commander of U.S. Central Command, briefed the defense ministers on what has been identified as needs, including more Special Operations troops, more training to help local forces counter improvised explosive devices and more training on how to build temporary bridges for military operations, said a senior U.S. defense official, speaking on condition of anonymity to discuss the private meeting candidly.

“There was agreement that this is a good moment to do more,” the senior defense official said.

Separately, Carter announced during a news conference Wednesday alongside Le Drian at the French version of the Pentagon that he has invited leaders from all 26 nations involved in the military side of the campaign against the Islamic State, along with Iraq, to meet in three weeks in Brussels, the home of NATO. The first-time meeting will be focused on how the war may be expanded to include more resources. That leaves out 37 other countries that are a part of the 63-member coalition in some way, but not contributing militarily.

“Every nation must come prepared to discuss further contributions,” Carter said of the countries invited to attend the meeting in Brussels.

The senior defense official described the planned meeting in Brussels as a “forcing function” that will move defense ministers toward assessing how their countries will participate in the fight against the Islamic State in the future. In addition to the countries whose defense ministers met in Paris, ministers from countries like the United Arab Emirates and Jordan, who have participated in the air war against the militants in the past, will be invited.

Le Drian said that the United States holds the leadership role in the fight against the Islamic State, but that the French are on the front lines of the battle with about 3,500 service members involved. Over the last few weeks, the Islamic State has suffered a series of defeats, providing reason to step up operations against the group with a consistent military strategy, he said.

Le Drian added that the cities of Raqqa in Syria and Mosul in Iraq — de facto capitals of the Islamic State — must be won back, but that the military coalition also must sever the militant group’s control of surrounding areas. The ideology of the group also must be combated, he added, noting the large numbers of people who have traveled to Iraq and Syria from across the world to join the ISIS.

Carter said there is no other defense minister who he has spent as much time discussing the Islamic State fight with than Le Drian, and that they discussed accelerating the campaign against the militants even before the terrorist attacks in and around Paris in November that killed 130 people.

The meeting came after a the arrival of an elite U.S. “expeditionary targeting force” in Iraq that is expected to include up to 200 Special Operations troops. It is not yet clear whether it has begun carrying out operations, but it is expected to conduct raids, collect intelligence and carry out other operations against Islamic State leaders.

Carter said Tuesday while flying to Paris that he thought it was likely the number of U.S. troops deployed to Iraq as military advisers will expand in coming months, as additional Iraqi military units and police must be trained to hold areas leading from Ramadi to Mosul. While the United States could deploy some, other countries will be involved, he said.

“I can’t give you a number, but I would [say it] will increase greatly as the momentum of the effort increases,” Carter said. “And that will be [focused on increasing the] throughput not only of Iraqi security forces, but also Iraqi police forces. And obviously, there are many countries that contribute to both of those training streams. The United States does, but most of the countries represented in the room when I meet with them will do that also.”

As of Jan. 10, the U.S.-led military coalition has carried out 6,341 airstrikes in Iraq and 3,219 in Syria, according to the Pentagon. Of those, the United States has carried out the majority, with 4,361 Iraq and 3,029 in Syria.

The rest of the military coalition has carried out 1,980 strikes in Iraq and 190 in Syria. The countries doing so in Iraq include the United States, Australia, Belgium, Canada, Denmark, France, Jordan, the Netherlands and Britain. In Syria, the nations that have carried out airstrikes include the United States, Australia, Bahrain, Canada, France, Jordan, Saudi Arabia, Turkey, the United Arab Emirates and Britain.

This story was originally published at 11:28 a.m. on the East Coast and subsequently updated.