The prime minister says the UK’s evacuation operation in Afghanistan will continue despite what he described as the “barbaric” terrorist attack at Kabul airport.
The Taliban says at least 13 people, including children, have been killed in the attack. Dozens of others are being treated in local hospitals.
Speaking after a meeting of the government’s emergency COBRA committee, the PM said members of the US military “very sadly have lost their lives” in the attacks, as well as “many Afghan casualties”.
At least three US service members have been killed in the attack, according to an American official.
The Ministry of Defence said there had been no UK military or government casualties reported so far.
Mr Johnson would not be drawn on who was suspected to be behind the bombings, but said “there were almost certainly members of the Taliban who were themselves killed in this attack”.
“I want to stress that this threat of a terrorist attack is one of the constraints that we’ve been operating under in Operation Pitting, in the big extraction that’s been going on, and we’ve been ready for it, we’ve been prepared for it,” he said.
“And I want to stress that we’re going to continue with that operation – and we’re now coming towards the end of it, to the very end of it, in any event.”
The PM added: “But, clearly, what this attack shows is the importance of continuing that work in as fast and as efficient manner as possible in the hours that remain to us, and that’s what we’re going to do.”
Mr Johnson said the conclusion from the COBRA committee meeting was that the evacuation programme should continue “in the way that we’ve been running it, according to the timetable we’ve got”.
He added: “That’s what we’re going to do because the overwhelming majority of those who are eligible have now been extracted from Afghanistan.
“We’re going to work flat out, the military, the Foreign Office teams, the Home Office, the Border Force teams that are there getting people through as fast as they can still.
“We’re going to keep going up until the last moment, but I want to repeat what I’ve been saying over the last few days: we also fully expect that those who want to leave Afghanistan after this phase one, if you like, are allowed to do that by the Taliban.”
The PM said the UK’s immediate priority was to “finish off this process of evacuation”, but then things would move into a “second phase” in which G7 and NATO nations will “engage with the Taliban to try to get a political process going that gives a more inclusive future, an inclusive and representative government for Afghanistan”.
An aviation notice advising airlines to avoid Afghan airspace under 25,000 feet has been issued by Transport Secretary Grant Shapps.
Labour leader Sir Keir Starmer described events in Kabul as devastating, adding: “Our thoughts are with all those killed and wounded, serving personnel supporting the evacuations and all those desperately trying to leave.”
Sir Ed Davey, leader of the Liberal Democrats, said: “Tragic and horrifying scenes in Kabul, my thoughts and prayers are with all those who have been injured and the families of the people who have been killed in these senseless attacks.”