EU chief Ursula von der Leyen on Saturday appealed to European Union states to take in Afghan refugees flown out from Kabul, promising financial support from Brussels.

"To those who cannot go back or stay home, we have to offer alternatives," said von der Leyen, after visiting a military base in northeast Spain that will serve as a reception centre for Afghans arriving from Kabul who worked for the EU.

"This means, first, that we must offer legal and safe routes globally, organised by us, to those who need our protection."

All EU states that had operated missions in Afghanistan needed to draw up adequate quotas so those who needed protection would get it, she said.

"The Commission stands ready to look into the necessary budgetary means to support EU member states who will step up and help resettle refugees," she added.

EU Council President Charles Michel, the bloc's foreign policy chief Josep Borell and Spanish Prime Minister Pedro Spanish also visited the base, at Torrejoin de Ardoz.

"Close to 150 people have been evacuated so far; our efforts on the ground continue to get all staff and dependants to safety," Borrell tweeted.

Sanchez said the centre would be used to process the arriving Afghans and their families before they are settled in EU countries, has a capacity for 800 people.

Some countries had already agreed to take in the former EU employees, including Denmark and some of the Baltic countries, he added, without elaborating.

For nearly a week now, Western countries have been scrambling to evacuate not just their own nationals but Afghans who worked for them and who fear reprisals from the new Taliban regime.