The two struck a pointed contrast on deploying ground troops to Iraq during the town hall held in New York on Wednesday by NBC News and Iraq and Afghanistan Veterans of America.
Democratic presidentaial nominee Clinton pledged that the US was "not putting ground troops into Iraq ever again, and we are not putting ground troops into Syria", while the Republican nominee disagreed, reported the Guardian.
Trump, who has long talked about the importance of "taking the oil" in the Middle East, said: "We would leave a certain group behind and they would take the various sections where they have the oil."
The forum came hours after Trump laid into Clinton as "trigger happy". During an address on defence spending in Philadelphia earlier in the day, the former reality TV star suggested there wasn't a country in the Middle East that Clinton did not want to invade -- an assertion he repeated on Wednesday evening.
The US currently has roughly 5,000 troops deployed in Iraq, mostly as official non-combat advisers for the Iraqi military, along with special operations forces. Navy and Air Force pilots also participate daily in air attacks on the Islamic State terrorist group.
The discussion took place a little under three weeks before the first Presidential debate on September 26.
In response to a question from the audience on military sexual assault, Trump cited his tweet from 2013 in which he suggested that the epidemic was a consequence of allowing women to serve in the military.
Trump also called for "a court system within the military", seemingly unaware that the military has always been governed by a court system separate from civilians.
When asked what he would do, if elected as President, to curb military sexual assault, Trump remained vague. "We have to come down very hard on that and do something about that," he said.
Trump also touched his bumpy relationship with various foreign leaders.
I think I would have a very, very good relationship with Putin: Trump
He further talked about his so-called "bromance" with Russian President Vladimir Putin, whom he repeatedly praised and cast as a better leader than Barack Obama.
Trump went on to characterise his relationship with Putin as mutually beneficial.
"If he says great things about me, I'm gonna say great things about him," he said. "I think when he calls me brilliant, I'll take the compliment. OK?
"I think I would have a very, very good relationship with Putin and a very good relationship with Russia."
Clinton, by contrast, sought to re-emphasise her foreign policy expertise while defending her legacy as Obama's Secretary of State.
The Democratic nominee repeated once more that it was "a mistake" for her to use a private email server while at the helm of the State Department.
"I have made no excuses for it. It was something that should not have been done," Clinton said.
Clinton struck a similar tone when discussing her support for the Iraq war, although not without pointing out that Trump also backed the invasion but has refused to acknowledge his support.
"I took responsibility for my decision," she said of her vote for the Iraq war. "My opponent has refused to take responsibility for his support."
However, Trump asserted that he had been against the war all along. Clinton also pointed out there was "no difference" between her position on Libya and that of Trump.
"He's on record extensively supporting intervention in Libya," she said.
Trump, in turn, criticised the Obama administration as pursuing "the dumbest foreign policy" he had ever seen.
"The Generals have been reduced to rubble," Trump said, when pressed on the assertion he made during his campaign that he knows more about Islamic State than military Generals.
Asked what his own strategy would look like against the militant group, Trump declined to comment.
"I have a substantial chance of winning -- make America great again," he said. "If I win, I don't want to broadcast to the enemy what my plan is."