"We should not be closed to the possibility of some advisors or support elements… the same way we have them on the ground in Iraq," Petraeus told the US Senate Armed Services Committee.
On Tuesday, Petraeus spoke to the Armed Services Committee about potential changes to US policy in the Middle East to defeat the Islamic State and otherwise advance US interests in the region.
Taking out Assad, Petraeus argued, will not require 165,000 troops, "but rather advisors in an ‘enclave’ similar to that of those on the ground in Iraq."
"In my judgment, increased support for the Iraqi security forces, Sunni tribal forces and Kurdish Peshmerga is needed, including embedding US advisor elements down to the brigade headquarters level of those Iraqi forces fighting ISIS [Islamic State]," Petraeus said.
Joint tactical air controls with certain Iraqi units, he added, in order to coordinate airstrikes for those units and advance the fight against the Islamic State.
On Tuesday, Russian Deputy Foreign Minister Gennady Gatilov said the United States must firmly assess the nature of cooperation between Russia and Syria, if it truly hopes to defeat the Islamic State.
Petraeus served as the commander of the US Central Command (CENTCOM) from October 31, 2008- June 30, 2010.