Two bombs exploded in crowded areas outside the airport in the Afghan capital, Kabul on Thursday. Officials at the Pentagon say 13 American service members were killed and there were a number of civilian casualties.
The bombs went off outside a gate, near where US and British forces have been stationed. Hundreds of people had gathered outside.
US officials say they believe suicide bombers associated with Islamic State militants carried out the attack.
The Americans and their allies had warned of such a threat. They had advised people to stay away from the airport.
The Taliban regained control of Afghanistan over the last few weeks. Afghans and foreign nationals have been scrambling to get out before American troops leave at the end of the month.