Last UK military flight leaves Kabul, 15,000 people evacuated

Britain's Defense Ministry said the last flight carrying UK army personnel has left Kabul, ending the evacuation mission. 

"We should be proud of our armed forces, welcoming to those coming for a better life, and… sad for those left behind," Wallace said on Twitter.

"Our obligation to them does not end with our leaving," he added.

With the UK's 20-year mission to Afghanistan coming to an end, Wallace said that there would be "many lessons to learn," but there were also "endless examples of amazing achievements."