And his message to Iraqi leaders was plain: US military power didn't solve Iraq's problems last time, nor will it now.
Hagel says Iraqi leaders and the people of Iraq know that only they can bring lasting peace to their country if they are resolved to do it.
Hagel made the comments yesterday after meeting Prime Minister Haider al-Abadi and other top Iraqi officials.
Hagel offered assurances that Washington is committed to helping Iraq regain the territory it lost to Islamic State fighters this year, and he emphasised the importance of building an international coalition to combat the extremist group.