The Army's top officer, who spent more than four years as a commander in Iraq, said it's been "frustrating" to see Iraq "falling apart" at the hands of the Islamic State terror group.
"I go back to the work we did in 2007 [through] 2010, and we got into a place that was really good," Army Chief of Staff Gen. Ray Odierno said in an interview Tuesday with Fox News. "Violence was low, the economy was growing, politics looked like it was heading in the right direction. We thought we had it going exactly in the right direction, but now we watch it fall apart. It's frustrating that it's falling apart."
Odierno, who commanded a division and a corps in Iraq before becoming the top U.S. commander in country, spoke to Fox News' Jennifer Griffin as he prepares to complete his tenure as chief and retire from the Army.
The U.S. withdrew from Iraq at the end of 2011, in accordance with a 2008 security agreement. Efforts to produce a new agreement between both governments failed after drawn-out talks, as U.S. officials pushed for immunity from local prosecution for any troops who remained.
When asked if the U.S. should have stayed in Iraq, Odierno said: "I think it would have been good for us to stay."
It's impossible to know how Iraq would have turned out or if keeping U.S. troops in Iraq would have stopped the rise of the Islamic State group, Odierno said.
"I believe that, I think, maybe, if we had stayed a little more engaged, I think maybe it might have prevented it," he told Fox News.
After the U.S. left, the Iraqis "went back to their normal mistrust between the groups that, I think, was fueled a little bit by Iran's influence in Iraq," Odierno said. "Now we're at a place where we now have fighting going on between different groups. So for me, it's tough to watch."
Fighting the Islamic State terror group is "a 10-year problem at least," Odierno said.
"Middle Eastern countries have to solve this problem," he said. "We have to build their capability, their capacity to solve that problem. We certainly can assist them, but they've got to want to solve this problem."
Odierno's remarks to Fox News echo what he said in late May when he spoke to reporters in Washington, D.C.
"It's incredibly disappointing to me, personally, what I've watched happen," he said at the time. "I really believed, at that time [in 2010], that in five years or so, Iraq would be doing very well. But, frankly, they fractured."