The diplomat leading the UK’s rescue mission in Afghanistan has said the Kabul airport evacuation effort is “without a doubt” his greatest international challenge.

Sir Laurie Bristow, British ambassador to Afghanistan, has won plaudits for staying in the Afghan capital to personally help process visas.

The experienced diplomat has relocated from the embassy in Kabul – which has been emptied following the Taliban takeover – to an emergency handling centre set up at the city’s airport to process the applications of those seeking to leave for the UK.

Sir Laurie Bristow
Sir Laurie Bristow, right, remains in Kabul to assist with efforts to repatriate people to the UK (FCO/PA)

Operation Pitting is supported by 1,000 British troops – including Paras from 16 Air Assault Brigade – as well as other Whitehall staff.

The Ministry of Defence said that nearly 4,000 people had been evacuated from Afghanistan since August 13.

Those repatriated include embassy staff, British nationals, those eligible under the Afghan Relocation and Assistance Policy (Arap) programme and a small number of nationals from partner nations.

In a statement issued by the Foreign Office, Sir Laurie said: “The scale of this effort is enormous and is without a doubt the biggest international challenge I have worked on as a diplomat.

“Lives are at stake and I am incredibly proud of the tenacious efforts of my team during these challenging times, with military and civilian staff working together to successfully evacuate thousands of people in the last week.

“We will continue to work tirelessly to get British nationals, Afghan staff and others at risk out of the country as quickly as possible as we also support Afghanistan’s long-term future.”

The Prime Minister on Friday paid tribute to Sir Laurie and his team, and also to Home Office, Border Force, Foreign Office and Ministry of Defence officials who have travelled to Afghanistan to aid repatriation efforts.

Mr Johnson said 1,000 people had been repatriated to the UK on both Thursday and Friday.

Sir Laurie Bristow
Sir Laurie Bristow, left, on the ground at Kabul airpot (FCO/PA)

It comes as US President Joe Biden signalled he wanted the evacuations completed by the end of the month as he prepares to withdraw all American troops – a move that would likely force Britain to wrap up its operation at the same time.

Mr Johnson told reporters after an emergency Government meeting that the situation in the central Asian country was “slightly better”, although the airport scenario has since worsened

Sky News said it had spoken to British troops at the airport who, having served in Afghanistan previously, said the queues, crushing and desperation of people to get out of the country were the worst scenes they had witnessed during their service.

Giving a breakdown of the 3,821 repatriated so far, the MoD said 1,429 individuals and their families have been relocated under the Arap scheme and 1,323 UK nationals and their loved ones have also now been brought to Britain via military and civilian charter flights since the operation commenced.

In addition, a further 1,069 individuals have been relocated from a third country.

Officials said they were continuing to “work closely” with US military partners  to “ensure the security and viability of the evacuation mission in Kabul”, with suggestions August 31 is the cut-off date for bringing people back.

It also comes amid reports of tension between Washington and London, with claims the UK Government was kept in the dark about the timetable for the US withdrawal of its armed forces.

Further British troops are being held “at readiness in the region and the UK” to move to Afghanistan “at speed” if required, the MoD said.