Pompeo called on the coalition to increase intelligence-sharing, repatriate and prosecute captured foreign fighters and accelerate stabilisation efforts so that ISIL remnants could reconstitute in Iraq, Syria or elsewhere.
"I think we have to look more closely at the allegations in this particular situation to find out what happened", he added.
He played down the USA planned withdrawal from Syria saying it was a tactical change rather than a retreat in their involvement, adding that: "America will continue to lead in giving those who would destroy us no quarter".
White House officials have pushed back, insisting the time has come for other nations to step up their contributions to the fight.
In December, Trump declared the Daesh terror group defeated in Syria and announced the USA troop pullout from the country but gave no timeline. Irving Locker, Joseph Reilly and Herman Zeitchik were among the forces who landed in France in 1944 on D-Day, the USA -led invasion that cost tens of thousands of lives but turned the tide of war against Nazi Germany and its allies.
Trump has reaffirmed his determination to pull out the roughly 2000 U.S. troops from Syria.
This claim was highly disputed by other world leaders who said the fight against IS was far from over.
House Speaker Nancy Pelosi, Trump's political nemesis, sat behind his left shoulder, offering only sparing applause. "We do not know whether we will achieve an agreement - but we do know that after two decades of war, the hour has come to at least try for peace", he said. A senior administration official said the Islamic State has been promoting an insurgency to destabilize northeastern Syria and Iraq. Votel also confirmed to committee members that he believes the remaining ISIS stronghold in Syria will be eliminated by the time of US troops drawdown.More news: Manchester United Is Right Club For Anthony Martial - Ole Gunnar Solskjaer
After Wednesday's hearing, the HASC's top Republican, Rep. Mac Thornberry, R-Texas, reiterated to reporters his disagreement with the president and credited military leaders with trying to minimize the risks "that ISIS could spring back to life".
President Donald Trump has criticized his predecessor's approach to fight against the Islamic State militant group (ISIS), which he said was within a week of total defeat.
"The struggle against terrorism is a shared fight", he added.
Iraq and Syria need hundreds of millions of dollars in aid, according to administration officials.
'I think that every American can be proud of the progress that we have made.and they can be confident that the USA and our coalition partners will continue to lean into the fight against any resurgence of ISIS in the future, ' he said.
He called on coalition partners to recommit to the goal of permanently defeating ISIS, and said the terror group must no longer pose a threat to their respective homelands.
Although Iraq declared victory over IS more than a year ago, the country's security forces continue to battle pockets of resistance across the country, sometimes with the help of coalition airstrikes.
The Kurdish-led Syrian Democratic Forces, who were at the forefront of the battle that crushed the Islamic State, have warned that they may no longer be able to guard prisons housing jihadists from France, Britain and other foreign countries after the USA withdrawal if Turkey attacks.
USA officials have repeatedly warned of Iran's destabilizing activities in Syria and across the Middle East, but officials from Baghdad maintain the US military presence in Iraq is the result of an agreement to combat terrorism, and that keeping an eye on Tehran is not part of the deal.