The Taliban on Tuesday said they would not agree to an extension of a looming deadline to evacuate Afghans from Kabul airport, even as Western countries said they were running out of time.

European nations have said they would not be able to airlift at-risk Afghans before the August 31 cut-off, and United States President Joe Biden has faced calls from all corners to extend the evacuation window.

But speaking at a press conference in the capital Kabul, Taliban spokesman Zabihullah Mujahid said the Islamist group would not agree to an extension, and told the US to stop evacuating skilled Afghans.

Mujahid also said female Afghan government workers should stay home until security conditions in the country improve.

US-led troops have ramped up operations to get thousands of people out of Kabul, after the Taliban warned they would not allow the US to extend the deadline for a complete withdrawal.

President Biden has said he would stick to the schedule, but faced growing pressure to negotiate more time for the evacuations.

Germany said on Tuesday that Western allies simply cannot fly every Afghan who needs protection out of Kabul before the cut-off date.

"Even if (the evacuation) goes on until August 31 or even a few days longer, it will not be enough to allow those who we, or the United States, want to fly out," Foreign Minister Heiko Maas told Bild TV.

Earlier France said it would have to end evacuations from Kabul's airport on Thursday if the US stuck to the deadline, and Spain said it would not be able to rescue all Afghans who served Spanish missions.

Britain, meanwhile, has said it will lobby for an extension at a virtual G7 summit later Tuesday.

They don't accept women

About 50,000 foreigners and Afghans have fled the country from Kabul's airport since the Taliban swept into power nine days ago, according to the US government.

Many Afghans fear a repeat of the brutal interpretation of sharia law that the Taliban implemented when first in power from 1996-2001, or retribution for working with the US-backed government over the past two decades.

The Taliban, who ended two decades of war with an astonishingly swift rout of government forces, has been publicly tolerant of the evacuation effort.

But on Tuesday Mujahid reiterated an earlier Taliban warning against extending the airlift.

He also said Americans were taking "Afghan experts" such as engineers out of Afghanistan.

"We ask them to stop this process," he said.

The Taliban achieved their stunning victory thanks to Biden pulling out nearly all American troops from Afghanistan, following through on a deal struck with the movement by then-president Donald Trump.

However, Biden was forced to redeploy thousands of troops after the fall of Kabul to oversee the airlift.

According to the Washington Post, US Central Intelligence Agency chief William Burns held a secret meeting in Kabul on Monday with Taliban co-founder Mullah Abdul Ghani Baradar, although no details were reported and neither the CIA nor the Taliban confirmed it.

Time is running out

The rush to leave Kabul has sparked harrowing scenes and left at least eight people dead.

Some have been crushed to death and at least one, a youth football player, died after falling off a plane. 

The German defence ministry said Monday an Afghan soldier was killed and three others wounded in a firefight with unknown assailants.

Margarita Robles, the Spanish defence minister, said the security situation was getting worse.

"The Taliban are becoming more aggressive, there is gunfire, violence is more obvious," she said in an interview with news radio Cadena Ser.

"The situation is frankly dramatic and besides, with each passing day, it is worse because people are conscious that time is running out."

Door-to-door hunt 

The Taliban have repeatedly claimed to be different from their 1990s incarnation, and have declared an amnesty for government forces and officials.

But an intelligence assessment conducted for the United Nations said militants were going door-to-door hunting former government officials and those who worked with US and NATO forces.

In the capital and other cities, the former insurgents have enforced some sense of calm, with their fighters patrolling the streets and manning checkpoints.

The Taliban are also intent on quashing the last notable Afghan military resistance to their rule, made up of ex-government forces in the Panjshir Valley, north of the capital.

The Panjshir has long been known as an anti-Taliban bastion. 

One of the leaders of the movement, named the National Resistance Front, is the son of famed anti-Taliban commander Ahmad Shah Massoud.