During an often heated exchange on Capitol Hill, a State Department official told House lawmakers that the brutal extremist group the Islamic State of Iraq and the Levant, or ISIL, is no longer “simply a terrorist organization—it is now a full-blown army.”

“ISIL is worse than al-Qaeda,” said Brett McGurk, the State Department’s deputy assistant secretary for Iraq and Iran. “ISIL is no longer simply a terrorist organization. It is now a full-blown army seeking to establish a self-governing state through the Tigris and Euphrates valley in what is now Syria and Iraq.”

McGurk’s appearance Wednesday before the House Foreign Affairs Committee was his second this year on the growing extremist threat facing Iraq and in turn, the United States.

“Since that last hearing, [ISIL] has done precisely what [the Obama administration] predicted it would: it has taken over most of Western Iraq, it has turned its sights on Baghdad, and it may be preparing to launch attacks against the United States,” said Chairman Ed Royce, R-Calif.

(Related: Hagel Declares ISIL Clear and 'Imminent Threat' to U.S.)

Since McGurk’s last appearance before Congress, ISIL has continued to plague Iraq with violence. In Baghdad late Tuesday, a suicide bomber detonated a truck packed with explosives at a checkpoint killing 31 and injuring another 58. ISIL militants claimed responsibility for the attack. More than 5,500 civilians have died in Iraq fighting this year alone, the United Nations said last week.

“We did see this coming,” said Royce, noting that the Iraqi government has been urgently requesting drone strikes against ISIL camps since August 2013. “And that makes it even more troubling that the administration didn’t do what was necessary to prevent [ISIL] from taking over such a large swath of Iraq.”

But McGurk pushed back against many lawmakers who have called for U.S. drone strikes to take out ISIL fighters as they proceeded south into Iraq from Syria.

“The first principle and the president’s policy is that we want to enable local actors to be able to secure their own space as best we can. That was also the desire of the Iraqi government,” McGurk said. U.S. surveillance flights have increased from one per month to now more than 50 per day, he added. “The information we have now on these networks is night and day from where it was in May when the request from the Iraqis first came in. And there is a significant risk, Mr. Chairman, of taking any military action without that level of granularity.”

Elissa Slotkin, Acting Principle Deputy Under Secretary of Defense for Policy, also cautioned against U.S. military action.

“There will not be an exclusively U.S. military solution to ISIL,” Slotkin said at Wednesday’s hearing. “Iraqis must do the heavy lifting.”

The interests of national unity and respect for the Iraqi constitution come before any considerations of military strikes, McGurk said, echoing Obama’s words from June.

The Obama administration’s Iraq policy, he explained, involves relying on the Iraqi government to work in accordance with its own constitution. He noted that the recent appointment of a new moderate Sunni speaker in Iraq’s parliament marked a promising turn toward securing the support of all the country’s political factions.

“They chose a speaker,” he said. “That kicked off a timeline for 30 days to choose a president. Once there’s a president, there’s a 15-day clock to name a prime minister. And then 30 days to form a cabinet.”

But lawmakers Wednesday didn’t appear to be terribly interested in the take that an Iraqi political solution be prioritized over a U.S. military one.

“[Iraqi Prime Minister Nouri al-Maliki] must go, and the sooner the better,” ranking member Rep. Eliot Engel, D-N.Y., said, reflecting many lawmakers' impatience with the divisive Shiite leader.

“There is a recognition in Iraq that from the center out, you’re never going to fully control all of these [ISIL-controlled] areas, particularly given the capacity of ISIL,” McGurk said. “And there is also recognition that locals alone and tribal forces alone cannot defeat ISIL. They need the support and resources of the central state…The people do not want to divide into three different countries or states. There is no easy solution for that. When you game it out, the consequences are actually quite serious.”

(Related: Can Another ‘Anbar Awakening’ Save Iraq?)

Rep. Engel disagreed with that assessment, but McGurk replied that his face-to-face meetings last week with Kurdish leaders in Irbil confirmed their support for a unified Iraq.

“Given the ISIL threat,” Slotkin added, “the strongest single blunt to that threat would be a strong, capable federal government in Iraq that’s actually able to exert control and influence to push back on that threat.”

“The administration is just paralyzed, they don’t know what to do,” former Air Force pilot and Iraq war veteran Rep. Adam Kinzinger, R-Ill. said. “Political solutions are not something that we can put in a microwave and expect to happen in a short amount of time.”

Rep. Gerald Connolly, D-Va., expressed his skepticism over what some have called the Obama administration’s “soft” approach in Iraq. “Ms. Slotkin, we’ve been [in Iraq] for 12 years, we poured a trillion dollars into the country, we’ve lost precious men and women in fighting there,” Connolly said, continuing, “How does one achieve this strong, central, effective, functional government in Baghdad?”

That’s exactly what Iraqi lawmakers are struggling with right now, Slotkin answered. “And as they form their government, they will have some fundamental questions that they will have to answer about the future of their state,” she said.

“I hope you’re right,” Connolly replied. “But the skepticism expressed in this committee is very bipartisan.”

Rep. Albio Sires, D-N.J., asked what Baghdad and the U.S. can expect of an Iraqi army—four divisions of which dropped their weapons and ran in the face of advancing ISIL fighters—that appears to lack will or direction. McGurk assured him those leaders have all since been fired.

“I will not underestimate the extreme challenge here,” he said. “ISIL is a highly-effective, sophisticated military organization. It is far better than the al-Qaeda in Iraq that we fought. And in order for the [Anbar] awakening to really get moving in those days, it took a lot of effort on our part to degrade that network which then allowed the awakening and the tribal networks to really rise up and fight it. So I think it has to be taken in parallel. There will have to be some military pressure against ISIL; at the same there has to be a new government with political accommodations made to isolate ISIL from the population. They have to run in parallel to be effective.”