The remaining flights over the weekend are expected to bring home British troops as well as the final small number of Afghan evacuees cleared to fly, defense sources said.
UK Ambassador to Kabul Laurie Bristow said in a video posted to social media that her team had “worked until the very last moment.”
Almost 15,000 people were flown to safety, he added, tweeting that “our commitment to the Afghan people will endure.”
Earlier, the Chief of the Defense Staff, General Sir Nick Carter, had said that the final stages of withdrawal and evacuation were the “most difficult” of all phases of war.
He added: “There must be a less and less rear guard protecting your back as you evacuate, and of course there comes a point when this is really the last plane to come out.
“There are all kinds of things that can go wrong” when the last planes go, like the “terrorist threat,” he said.
“You are the most vulnerable when your last plane is waiting to take off. “
Sir Nick warned Britain was “not out of the woods yet”, adding: “The operation will continue for a bit longer. But it has been a huge undertaking. “
The troops are working in the face of a “very demanding threat” while also focusing on “humanitarian work” with soldiers “holding a gun in one hand and a baby in the other.”
“It has been very difficult,” said Sir Nick.
“The point is, we always have that in mind.
“For the troops on the ground, they need to be constantly on the alert and constantly thinking about how they can refute the threat.
“I think we should hold our breath and think real hard about that last plane or several last loadings of planes and think about the challenge that is going to be for these very brave people who are trying to make their departure so safe and secure. orderly fashion as they can. “
Sir Nick, who spent nearly three years in Afghanistan, described his regret that the 20-year mission there ended with the Taliban in command and a serious terrorist threat.
He said of the withdrawal: “This is not how we hoped it would end, it is absolutely true. “
He added: “I think we’ve done an amazing job of evacuating as much as possible, but I’m afraid it’s absolutely heartbreaking that not being able to get everyone out.
“If they do manage to get out, they will always be welcome, but the terrible fact of life is that tough decisions have to be made. “
He recounted how Britain had failed to save all Afghans entitled to visit the UK, adding: “Not a day goes by that I don’t have a tear in it. ‘eye “.
US forces, which by far have the largest presence, will be the last to leave before a Tuesday deadline set by President Joe Biden.