NEW YORK (CBS DC) — Army Chief of Staff Gen. Ray Odierno says “Arab communities need to step up” the fight against Islamic State militants in Iraq and Syria, noting that Sunni/Shia fighting has prevented the U.S. from helping the Iraqi government take down the ISIS fighters.

Speaking with “CBS This Morning,” the U.S. Army chief said the training of Iraqi forces is the primary objective in taking down ISIS but the bigger issue is the “political problem” of regional Arab forces not uniting against ISIS. Odierno said the U.S. “can’t solve the problem itself” and the fight against ISIS could potentially last another decade.

“I don’t think it’s a new strategy…we’re just putting more people on the ground to help train the Iraqi forces,” said Odierno, detailing the recent addition of 450 American troops to eastern Anbar province. The addition brings the total of U.S. forces in Iraq to 3,550.

“We had this in a good place three or four years ago,” said Odierno, pointing to what he says is the root of the ISIS crisis. “Iraq was safe, the economy was growing, we turned it over to the Iraq government and I believe the Iraqi government has not been able to bring the different groups of people together…there’s this underlying Sunni, Shia issue and that’s what’s making this more difficult.”

“Until you solve that problem is doesn’t matter how many people you put on the ground,” said Odierno.

“Could I put 150,000 soldiers on the ground and defeat ISIS? Yes. But then what? But then what?” repeated Odierno. “We would be right back to where we are today…We need to solve the [Iraqi] political problem.”

Asked if the U.S. military is leaning toward a boots-on-the-ground approach in Iraq, Odierno said it is the Arab nations of the region that need to step up and help defeat ISIS.

“In order to solve this problem we need the Arab communities to solve this problem,” said Odierno. “The United States cannot solve this problem by itself. We need the Arabs to step up. We need them to understand we have extremism here and they have to help us.”

“It does come down to do they want to do this, do Shia fighters want to fight in the Sunni part of Iraq? I don’t know,” he said. “They need fighters willing to fight for Iraq…not a specific politician or religious fighting sect…trying to reach out to Sunni fighters to join.”

Odierno said the fighters need to feel a sense of loyalty or backing from the Iraqi government.

“They have to believe that the government will be there for them and so then they understand what they’re fighting for. We need the government to really start to reform itself…From the beginning we said this is going to take a long time,” he said, adding that President Obama had originally suggested 5 years to defeat ISIS.

“It’s a 3 to 5 to 7- 10 year problem; this is not going to be fixed overnight. And the reason it’s not going to be fixed overnight is they need to fix this problem,” said Odierno. “We can help them, and we’re willing to help them, but we went in and fixed it once.”