Joe Biden has warned those behind the terror attacks at Kabul’s airport: “We will not forgive, we will not forget, we will hunt you down and make you pay.”
The US president was speaking after it emerged that 13 US service personnel – most of them Marines – were among at least 73 people killed after two blasts and a gunfight outside the facility.
Of the 60 Afghans killed 28 were Taliban members according to a Taliban official.
Some 143 people, including 18 US personnel, were injured in the attack, which came 12 days into an effort to evacuate thousands of people – foreign citizens and Afghans – from Kabul.
The US and its allies have until the end of August to get out of Afghanistan and Mr Biden said more troops will be sent in if necessary.
Mr Biden said the Americans killed in the attacks were “heroes” who were “engaged in a dangerous, selfless mission to save the lives of others”.
Speaking from the White House on Thursday evening, Mr Biden said he had asked for plans to strike back at ISIS-K, the Islamic State affiliate believed to have been responsible for the attacks.
He said: “We will respond with force and precision at our time, at the place of our choosing.
“These ISIS terrorists will not win. We will rescue the Americans; we will get our Afghan allies out, and our mission will go on. America will not be intimidated.”
The UK’s Ministry of Defence has confirmed there were no fatalities among British military personnel or government workers.
UK defence sources said one of the blasts was by a hotel where British troops and journalists have been staying, followed by small arms fire, while the second explosion was near Abbey Gate.
Sky News Chief Correspondent Stuart Ramsay, who was reporting from the area earlier this week, said: “It was so very clearly a dangerous place to be because of the numbers of people coming through, and the fact that there are no real checks on what people are carrying or wearing to get through into this canal area.”
Ramsay said the attack “is not inside the airport proper (but is near) the perimeter wall of the airport, and it’s one road that leads to the processing area which is initially set up by the British.”
The attacks have increased the pressure on Mr Biden, who had justified the withdrawal as a means of preventing American deaths in what he described as Afghanistan’s civil war.
On 20 August, days after the Taliban took Kabul, Mr Biden told reporters that remaining in Afghanistan any longer could mean he would need to “send your sons, your daughters – like my son was sent to Iraq – to maybe die. And for what? For what?”
But instead of preventing bloodshed, the chaotic evacuation has now resulted in the first US deaths in action in Afghanistan in 18 months.
On Thursday evening, Mr Biden again stood by his decision to withdraw from Afghanistan, saying: “It was time to end this 20-year war.”
The deadline for withdrawal agreed between the Taliban and Donald Trump during his presidency last year had been May, but Mr Biden pushed this back to the end of August.
Some European leaders had called for the date to be moved back further but the Taliban warned earlier in the week that such a move would be seen by them as crossing “a red line” and would “provoke a reaction”.
Reuters news agency reported that evacuation efforts had accelerated, with planes taking off from Kabul regularly as the US and UK continued to try to get people to safety.
A number of other allies, including Canada and Germany, have announced their missions are over.
US General Frank McKenzie told a Pentagon news conference that about 5,000 evacuees were on the airfield awaiting flights and that as many as 1,000 Americans and many more Afghans were still trying to leave Kabul.
British Prime Minister Boris Johnson said on Thursday that the UK had evacuated more than 13,000 people from Afghanistan and operations would continue.
UK Foreign Secretary Dominic Raab added: “The UK and US remain resolute in our mission to get as many people out as possible. It is testament to the remarkable courage of our personnel that they continue to do so while under fire.
“We will not let the cowardly acts of terrorists stop us.”
At least 28 of the 60 Afghans killed in the attack were Taliban members, according to a spokesman.
Earlier, the group had condemned the attack, saying: “The Islamic Emirate strongly condemns the bombing of civilians at Kabul airport, which took place in an area where US forces are responsible for security.
“The Islamic Emirate is paying close attention to the security and protection of its people, and evil circles will be strictly stopped.”
ISIS-K (The Islamic State Khorasan) is an enemy of the Taliban, believing their laws are too soft.