WASHINGTON

 President Barack Obama said Monday that while progress has been made against Daesh in Iraq and Syria, the fight against the militants requires patience.

“This will not be quick,” Obama said at the Pentagon after meeting with his national security team. “ISIL is opportunistic, and it is nimble. In many places in Syria and Iraq, including urban areas, it's dug in among innocent civilian populations. It will take time to root them out,” Obama added using another name for Daesh.

The American president stressed gains made against the group in Iraq, including at Mt. Sinjar, the Mosul Dam, and in Kirkuk Province and in northern Syria’s Kobani and Tal Abyad. But he acknowledged that “there are also going to be some setbacks”, noting the group’s gains in Iraq’s Ramadi and central and southern Syria.

Earlier Monday, State Department spokesman John Kirby said Daesh has lost between 20 and 30 percent of the territory under its control in Iraq and Syria since last year.

Regarding a potential buffer zone in northern Syria, Kirby said that the notion that there are "huge rifts" with Ankara about the matter "is being overplayed."

"Turkey has, again, agreed to host a train-and-quite site inside Turkey, and they are lifting enormous weight to try to take care of millions of refugees from Syria inside their border," he said.

The U.S. announced last month that it would send an additional 450 troops to Iraq to train and assist local forces there, Obama said Monday that “there are no current plans” to further increase troop levels.

He said that while the U.S. has gotten better at thwarting mass attacks like the Sept. 11, 2001, attacks on the World Trade Center and Pentagon, the risk of lone-wolf militancy continues to pose a problem.

“These small individual lone wolf attacks or small cells become harder to detect and they become more sophisticated using new technologies. And that means that we're going to have to pick up our game to prevent these attacks,” Obama said.

Monday’s rare Pentagon meeting included Defense Secretary Ash Carter, Chairman of the Joint Chiefs Army Gen. Martin Dempsey, Central Command Commander Gen. Lloyd Austin, Chief of Staff Denis McDonough and National Security Advisor Susan Rice. Vice President Joe Biden also participated in the meeting via a secure line.