Afghanistan: United States hits back at Islamic State with airstrike

The United States has conducted an airstrike against Islamic State in the Afghan province of Nangarhar, just over a day after members of the terrorist group killed more than 180 at Kabul's airport.

The drone strike is understood to have successfully executed one member of Islamic State thought to be involved in planning attacks in Kabul, according to the US Central Command. On Friday, at least 169 Afghans and 13 US military officers were killed in suicide bombings by members of ISIS-K, an Islamic State affiliate. It's believed there were no civilian casualties as a result of Saturday's retaliation.

Sources told the Associated Press the strike was authorised by US President Joe Biden and ordered by Defence Secretary Lloyd Austin.

Friday's attack came as thousands continued to flock to the Afghan capital's international airport hoping to get on board evacuation flights organised after the Taliban overthrew the country's government earlier this month.

Following the attack, the worst day of casualties for the United States in Afghanistan in a decade, Biden promised revenge for the fallen.

"We will not forgive, we will not forget. We will hunt you down and make you pay," Biden said in remarks at the White House.

He had previously warned of the threat of terrorist attacks when justifying the US planning to pull out of Afghanistan on August 31. Staying any longer, he said, left troops vulnerable.

Security concerns led Western nations on Thursday, including New Zealand, to advise citizens and visa holders in Kabul to not go to the airport. 

ISIS-K is believed to be the most violent of Islamic State's affiliates, responsible for many atrocious attacks since its formation in 2015. A UN report from June said it still had up to 2200 fighters, despite Islamic State falling in recent years. It bases itself in Nangarhar, close to Kabul and the Pakistan border, allowing for drug smuggling.

As the Taliban - which ISIS-K opposes - took control of Afghanistan, many Islamic State members were released from jails.

The last flight by New Zealand's C-13 Hercules left Kabul on Thursday night. No New Zealand Defence Force personnel were in the capital at the time of the bombings. On Friday, the Government said 276 New Zealand nationals and visa holders had been evacuated to the United Arab of Emirates and were destined for New Zealand. A further 100 people, including Kiwis and Australians, were to soon be processed. 

"Our thoughts and condolences are with all of those in Afghanistan who have lost lives or suffered injuries, including US forces, our other partners on the ground, and the families and friends of all who have been affected by this appalling attack," Jacinda Ardern said.

"We strongly condemn what is a despicable attack on many innocent families and individuals who were simply seeking safety from the incredibly difficult and fragile situation in Afghanistan."

The short window of time for evacuations and the chaotic state of the airport meant that not everyone New Zealand wanted to evacuate could be. Cabinet will consider how else to support those still on the ground.