WALES, United Kingdom (CBSDC/AP) — Secretary of State John Kerry says there is a strategy to deal with the Islamic State of Iraq and Syria, criticizing those who lashed out at President Barack Obama who stated last week the White House did not have a strategy yet to deal with the terror group.

Speaking during a meeting in Wales about building an anti-ISIS coalition with other NATO nations, Kerry said the administration’s strategy is becoming clearer by the day on how to deal with terrorists who beheaded two American journalists, James Foley and Steven Sotloff.

“Contrary to what you sort of heard in the politics of our country, the president is totally committed; there is a strategy that is clear, becoming more clear by the day. And it really relies on a holistic approach to ISIL. That is to say that we need to do kinetic, we need to attack them in ways that prevent them from taking over territory, that bolster the Iraqi security forces, others in the region who are prepared to take them on, without committing troops of our own, obviously,” Kerry said, using an alternate acronym for the Islamic State.

Republicans seized on Obama’s remark last week that “we don’t have a strategy yet” to dealing with ISIS in Syria to argue the president lacks a coherent approach to fighting the extremist group.

Kerry noted there has been success against ISIS in Iraq with targeted U.S. airstrikes.

“There are kinetic operations we can run in direct support of Iraqi security forces. And we’ve proven the model in the last weeks – breaking the siege on Sinjar Mountain, breaking the siege of Amirli, breaking of momentum that was moving towards Erbil, and in effect picking up enough intel to understand that the minute we hit them, these guys are not 10 feet tall,” Kerry explained.

“They’re not as disciplined as everybody thinks. They’re not as organized as everybody thinks. And we have the technology, we have the know-how. What we need is obviously the willpower to make certain that we are steady and stay at this.”

Kerry reiterated that they do not want to put boots on the ground to combat ISIS.

“I think that’s a redline for everybody here, no boots on the ground. Nevertheless, there are many ways in which we can train, advise, assist, and equip,” Kerry said.

The secretary of state warned that they cannot leave the terror group intact just for them to keep coming back.

“There is no contain policy for ISIL. They’re an ambitious, avowed genocidal, territorial-grabbing, Caliphate-desiring, quasi-state within a regular army,” Kerry said. “And leaving them in some capacity intact anywhere would leave a cancer in place that will ultimately come back to haunt us. So there is no issue in our minds about our determination to build this coalition, go after this.”

Kerry said that NATO nations must go after ISIS’ funding and that they must be committed on helping militarily and contributing intelligence advisers to combat the terror group. White House aides tell CBS News that NATO will pledge military assistance as Obama meets with European leaders and Jordan’s King Abdullah.

“So we’re convinced that in the days ahead we have the ability to destroy ISIL. It may take a year, it may take two years, it may take three years. But we’re determined it has to happen,” Kerry said.

Deputy national security adviser Ben Rhodes also told CBS News that the next presidential administration will have to destroy the terror organization.

“It’s clearly going to take a very long time to ensure that you’ve eliminated that threat,” Rhodes told CBS News.

Kerry’s comments come as the Iraqi Defense Ministry claims that a U.S. airstrike near Mosul killed Abu Hajar al-Sufi, a top lieutenant to ISIS commander Abu Bakr al-Baghdadi. The White House has yet to confirm his death.

“We are very careful not to make declarative statements until we know with certainty that someone like that, who’s a very high value individual in the organization, has been taken out,” Rhodes told CBS News. “Any time that there’s a leader taken off the battlefield in a terrorist organization like that, it does have an impact on their ability to operate as effectively as they did before.”

The heightened urgency reflected fears that the Islamic State was growing stronger in its quest to create a caliphate territory in the Mideast and systematically kill any who resist. The group is considered even more merciless toward its enemies than the al Qaeda terror network, and intelligence officials across the world warn that it may soon seek to seed its violence beyond its declared borders.

So far, the Islamic State has beheaded two American journalists it held captive for what the militants called payback for more than 120 U.S. airstrikes on its assets in northern Iraq since Aug. 8. Foley and Sotloff were two of what the State Department has described as “a few” Americans still being held hostage by the group. The Islamic State also had threatened to kill a British man it is holding hostage.

In the Sotloff video, a masked militant warns Obama that as long as U.S. airstrikes against the Islamic State group continue in Iraq, “our knife will continue to strike the necks of your people.”

“I’m back, Obama, and I’m back because of your arrogant foreign policy towards the Islamic State, because of your insistence on continuing your bombings … and on Mosul Dam, despite our serious warnings,” the executioner said. “You, Obama, have but to gain from your actions but another American citizen. So just as your missiles continue to strike out people, our knife will continue to strike the necks of your people.”

Obama administration officials maintained that the U.S. will not launch a ground war against the Islamic State militants. But they stopped short of ruling out airstrikes against the group in its safe haven in Syria, as the U.S. has resisted for years. The U.S. has been conducting airstrikes against ISIS in Iraq.

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