U.S. Secretary of State Antony Blinken is pressing the Taliban to allow charter flights carrying would-be evacuees to leave Mazar-e-Sharif.

Blinken said Wednesday that the Taliban aren't permitting the flights' departure because they claim that some of the passengers don't have the required documentation.

He added: "While there are limits to what we can do without personnel on the ground, without an airport with normal security and procedures in place, we are working to do everything in our power to support those flights and to get them off the ground."

He said those efforts include working with advocates and lawmakers to help coordinate their efforts and offer guidance, and helping to arrange landing rights and liaise with other countries in the region on overflights.

He also submitted to the Taliban that: any legitimacy, any support will have to be earned" after the group named an interim government.

Blinken spoke after he and his German counterpart on Wednesday hosted a virtual meeting of ministers from 22 countries as well as NATO and the European Union.

Blinken reiterated the cautious initial U.S. response to the Taliban's naming Tuesday of an interim government line-up.

He said a provisional Afghan cabinet was not the inclusive government the Taliban had promised and that the Islamist group needs to earn the international legitimacy and support it seeks.

(With input from agencies)