Ministers have warned that extending the evacuation in Afghanistan risks turning Kabul into a “war zone”, after the Taliban threatened “consequences” for Western troops who stay beyond next week’s withdrawal deadline.

Boris Johnson will use a meeting of G7 leaders on Tuesday to push President Biden to extend the August 31 deadline for the US withdrawal.

But UK ministers are increasingly resigned to having to conclude the UK evacuation from Kabul by the end of the week amid increasing security fears.

Ben Wallace, the British defence secretary, said on Tuesday morning that it is “unlikely” the 31 August deadline to pull troops out of Afghanistan will be extended as it gets “more and more dangerous”.

Speaking to Sky News, he said: “As we get closer it’s correct to say the security risk goes up, it gets more and more dangerous.

“Add-on groups and other terrorist groups like ISIS would like to be seen taking credit, would like to be seen chasing the West out of Afghanistan – that will feed their narrative and ambitions.”

Wallace said that although the Taliban control the outer ring outside the airport, which makes it harder for ISIS to get through, the UK troops are still “very vulnerable should a terrorist choose to do something”.

His concern was echoed by James Heappey, the armed forces minister, who said that extending beyond a week today risked turning Kabul into a “war zone”, with soldiers attempting to manage the evacuation while fending off potential Taliban attacks.

Sir Laurie Bristow, Britain’s ambassador to Afghanistan, also warned MPs that remaining longer would “provoke a reaction”, describing the Taliban’s commitment to the 31 August deadline as “uncompromising”.

The warnings came after Taliban spokesman Suhail Shaheen told Sky News that the evacuation effort continuing in Afghanistan past the end of the month would be a “red line” and would “provoke a reaction”, which the Taliban leadership would decide.

“Foreign forces should withdraw on the deadline they have announced earlier. Otherwise, it is a clear violation.”

A total of 7,109 people have now been moved from Afghanistan by the RAF, and UK forces are now racing against the clock to rescue the remaining UK citizens and local allies from Kabul airport before next week’s deadline.

One government source told The Times that the “vast majority” of the 4,000 British passport holders, Afghan interpreters and other support staff in Afghanistan were expected to have been evacuated by the end of the week.

But Wallace admitted: “Our focus is to get as many people out… but the scale of the challenge means that not everyone will get out. We are ruthlessly prioritising people.”