The United States underestimated the rise of the Islamic State in Iraq and Syria, President Obama said during an interview, broadcast Sunday night, in which he also acknowledged the Iraqi army's inability to successfully tackle the threat.

On CBS's "60 Minutes," correspondent Steve Kroft referred to comments by James Clapper, the director of national intelligence, in which he said, “We overestimated the ability and the will of our allies, the Iraqi Army, to fight.”

“That's true. That's absolutely true,” Obama said. “Jim Clapper has acknowledged that I think they underestimated what had been taking place in Syria.”

Obama blamed the ongoing turmoil in Syria for the rise of the Islamic State, also known as ISIL.

“Essentially what happened with ISIL was that you had al-Qaeda in Iraq, which was a vicious group, but our Marines were able to quash with the help of Sunni tribes. They went back underground. But over the past couple of years, during the chaos of the Syrian civil war, where essentially you have huge swaths of the country that are completely ungoverned, they were able to reconstitute themselves and take advantage of that chaos,” he said. "And so this became ground zero for jihadists around the world."

The president made clear the intentions of the campaign against the Islamic State.

“We just have to push them back, and shrink their space, and go after their command and control, and their capacity, and their weapons, and their fueling, and cut off their financing, and work to eliminate the flow of foreign fighters,” he said.

The president denied the United States is fighting another war. "We are assisting Iraq in a very real battle that's taking place on their soil, with their troops. But we are providing air support and it is in our interest to do that," he said.

Having built a coalition of 60-plus nations to fight against the Islamic State, Obama pointed out that the United States is still the go-to government for nations in need of assistance.

"America leads, we are the indispensable nation. We have capacity no one else has. Our military is the best in the history of the world," he said. "And when trouble comes up anywhere in the world, they don't call Beijing. They don't call Moscow. They call us. "

Acknowledging that the Islamic State has been "very savvy in terms of their social media," Obama said it is important to recognize that "part of our solution here is going to be military" but added that he hopes for a political settlement in the future.

“What we also have to do is we have to come up with political solutions in Iraq and Syria in particular, but in the Middle East generally, that arise in an accommodation between Sunni and Shia populations that right now are the biggest cause of conflict, not just in the Middle East, but in the world,” he said.

Obama refused to speculate on what would happen if the Iraqis fail to tackle the threat from the Islamic State.

"We're just getting started. Let's see how they do. I think that right now, we've got a campaign plan that has a strong chance for success in Iraq. I think Syria is a more challenging situation."

Obama admitted that crises with Ebola as well as Syria, Iraq and Ukraine have made this a "significant" period of his presidency. "You know, we've had challenges before. And we've overcome them," he said.

Concerning Russia, Obama said he has always had a "business-like relationship" with President Vladimir Putin, one that is "blunt" and "firm."