Any extension to the deadline for withdrawal from Afghanistan would cross a red line that will lead to “consequences”, the Taliban has warned.

The United States had set August 31 as the end point, to ensure the US presence had ended before the anniversary of September 11.

But Boris Johnson is planning to personally appeal to Joe Biden for a delay to the withdrawal of US forces from Afghanistan, after the chaos caused by the short timeline led to seven people being killed in the crush at Kabul airport.

The Prime Minister will use an emergency G7 meeting on Tuesday to press the case for a delay, after attempts by both Foreign Secretary Dominic Raab and Defence Secretary Ben Wallace to ask the same of their US counterparts fell on deaf ears.

However, Taliban spokesperson Dr Suhail Shaheen told Sky News: “It’s a red line. President Biden announced that on 31 August they would withdraw all their military forces. So if they extend it that means they are extending occupation while there is no need for that.”

He added: “If the US or UK were to seek additional time to continue evacuations – the answer is no. Or there would be consequences. It will create mistrust between us. If they are intent on continuing the occupation it will provoke a reaction.”