France and Switzerland have halted repatriations of Afghans, whose asylum requests fail because of security concerns, as the country descends into civil war.

The move comes as the Taliban have taken the strategic Afghan city of Ghazni just 150km from Kabul.

Taliban fighters could isolate Afghanistan's capital in 30 days and possibly take it over within 90, a US defence official cited US intelligence as saying.

France halted expulsions of migrants to Afghanistan in early July because of the worsening security situation there, a spokeswoman for the Interior ministry said today.

The spokeswoman also said that France was closely monitoring the situation with its European partners.

Switzerland also halted repatriations of Afghans.

"The State Secretariat for Migration suspends repatriations to Afghanistan until further notice due to the changed situation in the country," the agency said on Twitter.

"No new expulsions will be ordered. Preparations for repatriation will only be continued in the case of persons who have committed a criminal offence."

The issue of repatriating Afghans has divided Europe.

Greece said yesterday that the European Union was in no position to deal with a repeat of the 2015 migration crisis during the Syrian civil war, and must try to keep people from fleeing the conflict in Afghanistan.

Germany won't give money to Afghanistan if Sharia law introduced - foreign minister

Meanwhile, Germany will not provide any financial support to Afghanistan if the Taliban takes over power in the country and introduces Sharia law, its foreign minister told broadcaster ZDF today.

"We provide €430m every year, we will not give another cent if the Taliban takes over the country and introduces Sharia law," Heiko Maas said.

Elsewhere, Denmark has agreed to evacuate current and former employees of the Danish embassy or Danish armed forces in Afghanistan due to the worsening security situation, the government has said.

Denmark will grant people who have been employed in the previous two years and their close relatives temporary residence permits for two years, the government said.

"The security situation in Afghanistan is serious. The Taliban are gaining ground and developments are accelerating faster than many had feared," the government said in a statement.

"We have a common responsibility to help the Afghans who are now threatened due to their connection to and contribution to Denmark's engagement in Afghanistan," it said.

The Danish defence ministry said last week that 40 former and current employees at the Danish embassy in Kabul and four translators had asked for help.

Denmark, a close ally of the United States, has fought alongside US forces in Afghanistan since 2002.