The Taliban has warned there will be "consequences" if the United States and its allies try to remain in Afghanistan beyond a withdrawal deadline next week.

Thousands of troops have poured back into the country to oversee the chaotic evacuation of foreigners and Afghans from Kabul international airport. Pressure is also mounting on U.S. President Joe Biden to extend an August 31 deadline for full withdrawal.

Pentagon spokesman, John Kirby, says "the goal is to get as many people out as fast as possible… the focus is on trying to do this as best we can, by the end of the month." 

However, Biden is under pressure both domestically and from foreign allies to extend the military withdrawal deadline. 

Speaking to British media, Taliban Spokesman, Suhail Shaheen, says that any foreign military presence beyond the agreed deadline would be "extending occupation" and “there will be consequences” 

He warned “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."

The spokesman added: "If the U.S. 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."

The Taliban are currently working on forming a government, but two sources within the movement say there will be no announcements on a cabinet until the last U.S. soldier has left Afghanistan.

"It has been decided that the formation of the government and cabinet will not be announced as long as a single U.S. soldier is present in Afghanistan" the Taliban sources confirmed. 

Meanwhile, U.S. State Department spokesman, Ned Price, has told reporters that the future control of Kabul airport has been a topic of discussion with the Taliban. Price says the airport, which is currently under U.S. military command ahead of the publicly announced evacuation deadline, has been discussed with allies and other partners as well.

Price added "there is actually agreement between and among all these actors, of course between United States and our partners and allies, but also with the Taliban, that all of our interests would serve with a functioning airport."

In other developments, British Foreign Secretary, Dominic Raab, told the Telegraph newspaper, that London will use all possible means to address the situation. He said "we will use all of the levers at our disposal, including sanctions, aid and access to international finance system, and we are rallying our international partners around these shared priorities" 

Critics are warning that preventing aid from flowing to the country will trigger widespread violence in Afghanistan. 

Raab added that "we are pressing the permanent members of the UN Security Council to agree some parameters on the way forward. We are working with vital regional partners like India and Pakistan".

The Taliban seized power earlier this month from a U.S.-backed government in Afghanistan, heralding a return to the group’s rule of the country two decades ago.