The Obama administration's apparent miscalculation of the threat posed by Al Qaeda-aligned militants in Iraq drew severe criticism Thursday from top Republican lawmakers, who accused President Obama and his national security team of "taking a nap," warning "the next 9/11 is in the making."

Amid criticism from lawmakers, the White House appeared to open the door to the possibility of U.S. airstrikes, but stressed that sending American ground troops is not an option.

"We are not contemplating ground troops," Press Secretary Jay Carney said. "We are assessing what we can provide additionally."

The administration once again appears to have been caught off guard by an explosion of violence in a country U.S. forces helped liberate from a dictator. Al Qaeda-aligned Sunni militants were advancing south and threatening to move on Baghdad on Thursday after overrunning the northern Iraq cities of Mosul and Tikrit -- with Iraqi government forces in rapid retreat.

GOP lawmakers vented that advances made by the militant Islamic State of Iraq and Syria (ISIS) are confirming their "worst fears" about what would happen in the wake of the Obama-ordered U.S. troop withdrawal in 2011.

"What's the president doing? Taking a nap," House Speaker John Boehner snapped, before abruptly ending his weekly press conference on Thursday.

Sen. Lindsey Graham, R-S.C., said Iraq is "collapsing," calling it another potential Benghazi and urging the president to address the American people.

"The next 9/11 is in the making," Graham said.

Obama, asked about the violence in Iraq, said Thursday that the U.S. can't be "everywhere all the time," but said he's concerned about what he described as an "emergency situation." He said his administration is in close consultation with Baghdad, and acknowledged they "need more help" from the U.S. and international community.

"My team is working around the clock to identify how we can provide the most effective assistance to them. I don't rule out anything," Obama said.

Carney later clarified that the president, in his comment, was referring to the question of airstrikes.

White House and State Department officials earlier said the administration is considering sending additional aid, but have not specified what that might be. The Iraqi government reportedly is seeking U.S. airstrikes. Republican lawmakers and military analysts are urging the administration to quickly piece together a gameplan.

Sen. John McCain, R-Ariz., said Thursday that the current national security team is a "failure," urging Obama to get a "new team." He also took a shot at Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, saying: "We need a new chairman."

The escalating violence follows repeated assurances by the Obama administration that Al Qaeda is "on the run" and that its offshoots are not the threat they're made out to be.

As recently as Monday, State Department spokeswoman Marie Harf said of the situation in northern Iraq, "I don't get the sense that they're gaining a lot of territory."

Obama also brushed off concerns about Al Qaeda affiliates during an interview with The New Yorker, in a piece published in January.

"If a jayvee team puts on Lakers uniforms, that doesn't make them Kobe Bryant," the president said. That was in regard to concerns, at the time, that Islamist militants had taken over Fallujah -- the comment also followed Islamist militants overrunning the U.S. compound in Benghazi, Libya, killing four Americans.

Yet in Iraq, militants with ISIS have made considerable gains since January. (They were listed in 2004 by the State Department as a terrorist organization under their old name, Al Qaeda in Iraq, shortly after the group formed.)

Gen. Jack Keane, former Army vice chief of staff and Fox News military analyst, said the administration has not put enough effort into forming a "comprehensive strategy" to partner with governments in the region to share intelligence and battle Al Qaeda affiliates.

"This caliphate exists, and it will be the most menacing thing in the Middle East if unattended," Keane said.

He acknowledged that the administration has "decimated" the Al Qaeda leadership in Pakistan to a degree. But he said: "The fact of the matter is the Al Qaeda and its affiliates ... is on the rise in the Middle East and in Africa."

Keane also said the U.S. lost leverage with Iraqi Prime Minister Nouri al-Maliki, whom Keane said needs to be saved "from himself." U.S. lawmakers have faulted Maliki's Shiite-led government for alienating the Sunni minority, in turn fueling tensions and giving Sunni militants an opening to exploit.

The Wall Street Journal reported that, privately, administration officials acknowledge they were caught off guard by the sudden developments in northern Iraq, where security forces abandoned their posts and militants overran key locations.

Military leaders reportedly said they thought Iraq's forces could hold off ISIS -- they were wrong.

Amid the deliberations, congressional Republicans continue to fume over the administration's response to the terror attack in Benghazi in 2012, for which nobody has yet been brought to justice, and have launched a formal select committee investigation.

The developments also follow President Obama foreign policy speech last month at the U.S. Military Academy at West Point where he backed a policy of restraint abroad and called for a wind-down of U.S. "military adventures."

Few expect that U.S. ground troops would be dispatched to Iraq, no matter how dire the situation becomes.

At issue now, among other things, is whether to provide more military aid and approve airstrikes. Maliki reportedly has sought U.S. airstrikes, but so far has been turned down.

A statement from the National Security Council made no commitment.

"We are not going to get into details of our diplomatic discussions but the Government of Iraq has made clear that they welcome our support in their effort to confront [ISIS]," spokeswoman Bernadette Meehan said. "We have expedited shipments of military equipment since the beginning of the year, ramped up training of Iraqi Security Forces, and worked intensively to help Iraq implement a holistic approach to counter this terrorist threat.  Our assistance has been comprehensive, is continuing, and will increase."

White House Press Secretary Jay Carney, in a statement overnight, offered "condolences" to the families of those killed, but did not specify what actions the administration would take.

"The United States will stand with Iraqi leaders across the political spectrum as they forge the national unity necessary to succeed in the fight against ISIL," he said, adding "we will also continue to provide, and as required increase, assistance to the Government of Iraq to help build Iraq's capacity to effectively and sustainably stop [ISIS's] efforts to wreak havoc in Iraq and the region."

To date, the U.S. has provided considerable military assistance. The State Department said Wednesday that that has included: 300 Hellfire missiles, millions of rounds of small arms ammunition, machine guns, grenades, rifles and more. Officials say the U.S. also supplied Bell IA-407 helicopters and is set to send over F-16 fighter jets.

A statement from Sens. John McCain, R-Ariz.,; Lindsey Graham, R-S.C.; and Kelly Ayotte, R-N.H., blamed the current situation on the U.S. decision to withdraw all troops from Iraq.

"We call on the president to explain to Congress and the American people how he plans to address the growing threat to our homeland and our national security interests posed by the rapidly expanding Al-Qaeda safe haven in Iraq and Syria," they said.