Countries that were involved in the NATO mission in Afghanistan have a "duty of care" to Afghans in danger under Taliban rule and should take them in as refugees, the EU executive said on Thursday.

The message from the European Union is that "we have a duty to help those who are particularly at risk in Afghanistan, be it before or after the deadline" on Tuesday, ahead of which evacuations will have been halted, a European Commission spokesman said.

In a sign of Europe's concerns about an outflow of fleeing Afghans, the Slovenian presidency of the EU announced an emergency meeting of EU interior ministers will be held in Brussels on Tuesday to focus on the fall-out from Afghanistan.

The EU is "working on a comprehensive approach on Afghanistan," one Commission spokesman, Christian Wigand, told reporters.

It includes using an existing EU-US-Canada-UN resettlement forum to secure promises to take in quotas of Afghan refugees.

Another spokesman, Eric Mamer, said "specific pledges for quotas" were expected up to a cut-off date of mid-September.

Vulnerable Afghans should be given "safe pathways" to Europe and should "expect that member states or countries that participated in particular in the NATO mission would have a duty of care" towards them, he said.

Of the 36 countries that participated in NATO's "Resolute Support" Mission in Afghanistan, 22 of them were EU member states, including Denmark, Germany, Greece, Hungary, Italy and Poland.

Some of the non-EU countries that participated in the NATO mission were Albania, Australia, Britain, Canada, the United States and Turkey.

Mamer noted that European Commission chief Ursula von der Leyen was "calling on the states that took part in the NATO mission to offer resettlement".

The European Commission said it has flown out all of its staff from Afghanistan who are EU citizens except for a "core team" that continues to support evacuation efforts.

A spokesman, Peter Stano, said more than 400 local Afghan staff and family members had been evacuated, but a number he would not specify still wanted to leave.