More than 120,000 vulnerable people were evacuated from Afghanistan following the takeover by the Taliban. US and British forces led the humanitarian mission and no longer have a military presence on the ground after 20 years of fighting.
The rushed operation ended on August 31 and military personnel abandoned billions of military weapons and left hundreds of Americans and others eligible for relocation in the UK stranded.
British and US officials are engaged in talks with the Taliban to secure a safe passage for those still looking to flee.
The threat posed by terror groups in the region was demonstrated last week when a suicide bomber killed more than 100 civilians, including 13 US military personnel, near Kabul airport.
The Islamic State Khorasan, also known as ISIS-K, claimed responsibility for the attack, and a foreign policy expert has warned some militants may try to enter the West.
Dr Christian Emery, an expert on international relations and foreign policy analysis at the University College London, said ISIS fighters could attempt to use forged documents to leave the region, but downplayed the chances of it being successful.
He told Express.co.uk: “The Taliban’s willingness to cooperate with the US military in expediting the evacuation of Western personnel and their Afghan colleagues suggests to me that they do not think that taking fight to the American homeland would be in their interest.
“Such an act would create huge domestic pressure for Biden to redeploy the American military into Afghanistan, which is fundamentally not what the Taliban want.
“Other groups, such as The Islamic State Khorasan, a splinter group of ISIS mostly comprised of Taliban defectors and Pakistani jihadists, may be attempting to enter the West by forging evacuation papers – but it strikes me as a low risk.
“Firstly such individuals have to evade both Taliban checkpoints and Western vetting processes, and even if they do get to the West there’s no evidence that their organisation has the support networks or the logistical means to launch attacks in the West.
“Since the 9/11 attacks, no foreign terrorist organisation has successfully directed and carried out a deadly attack inside the US.
“But the chance of another terrorist attack in or around Kabul airport sadly remains very high.”
Mr Raab said the UK will not recognise the Taliban in the “foreseeable future” but said there is an “important scope for engagement and dialogue”.
Mr Raab added he had “good conversations” with Qatari Emir Sheikh Tamim bin Hamad Al Thani about the “workability” of rescue flights resuming.
Sir Simon Lawrance Gass, the chair of the Joint Intelligence Committee, has also been deployed the Middle East to assist the negotiations.
A Downing Street spokesman said: “The Prime Minister’s special representative for Afghan transition, Sir Simon Gass, has travelled to Doha and is meeting with senior Taliban representatives to underline the importance of safe passage out of Afghanistan for British nationals, and those Afghans who have worked with us over the past 20 years.”