WASHINGTON — Defense and foreign ministers from more than 30 nations are gathering in Washington to plan the next steps in the fight against the Islamic State and to determine what more they can do as the fights for key cities in Iraq and Syria move forward.

Defense Secretary Ash Carter was to meet with his counterparts today to discuss how they can accelerate the campaign and build on some of the momentum, particularly in Iraq. The meeting comes as coalition and Iraqi security forces are preparing to eventually attempt to retake the northern city of Mosul.

The meeting of defense ministers at Joint Base Andrews just outside Washington, D.C., will be the fourth time that Carter has convened an anti-Islamic State coalition meeting.

On Thursday, for the first time, Secretary of State John Kerry will host a joint meeting of defense and foreign ministers in the counter-IS coalition. They are expected to talk about the coordination of political and military efforts, including counter-terrorist financing, combating the flow of foreign fighters, and the stabilization of cities and towns that have been freed from Islamic State control.

“We are succeeding on the ground in Iraq and Syria but we have a lot of work to do,” said Brett McGurk, the president’s special representative to the counter-ISIL coalition. “This is an enormous challenge that will be with us for years to come.”

He told reporters that the situation in Libya and a rise in the number of foreign fighters there will be one major focus of the meeting on Thursday.

“Libya is incredibly complicated to say the least,” he said, noting that until six months ago the country was without a functioning central government. “We have some momentum, the discussion will be how to build on this momentum.”