General Kenneth McKenzie, the head of US Central Command, has placed the blame for the attacks on the ISIS terrorist group and warned that the threat of more attacks is “extremely real.”

“We expect those attacks to continue, and we’re doing everything we can to prepare for those attacks.”

McKenzie said the United States was prepared to use attack aircraft , including AC-130 gunships to defend the airport if necessary. "We'll be prepared to do that, should it become necessary to defend the base," he said.

He said the mission to fly out American citizens and at-risk Afghans who helped US troops from Kabul airport would continue undeterred by the twin bombings that killed 11 marines and a medic, and injured 15.

Local reports put the total death toll including civilians who were killed in the suicide bombings at around 60, with more than 100 injured.

McKenzie highlighted concerns that ISIS is seeking to get a vehicle-based suicide bomb onto the airport where almost 6,000 American service members are managing the evacuation effort.

He also mentioned that the terrorists had plans to “lob” rockets into the airport, but said anti-rocket systems in place will be able to neutralize that threat.

A Taliban official told Reuters the group arrested an ISIS fighter at the airport a few days ago and under interrogation he told them about plans for attacks. In response, the Taliban said it postponed gatherings in public places and advised its top leaders not to gather.

McKenzie said in an attempt to limit overall risk, the US has asked the Taliban to extend its security perimeter and close down a number of streets headed to the airport.

However, this is expected to make it more difficult for people to reach the airport for evacuation.

American leaders have reached “out to the Taliban who are actually providing the outer security cordon around the airfield, to make sure they know what we expect them to do to protect us and we will continue to coordinate with them as they go forward,” McKenzie said.

He said he doesn’t believe the Taliban helped plot the attack, given both tensions between the Taliban and ISIS and the fact the Taliban have a vested interest in seeing the Americans leave the country.

“I don’t think there’s anything to convince me” that the Taliban let it happen, he said. “They have a practical reason for wanting us to get out of here by the 31st of August. As long as we’ve kept that common purpose aligned, they’ve been useful to work with.”