The United States and its NATO allies are exploring a possible international effort to help secure the airport in Afghanistan’s capital after American troops withdraw from the country, the top US general said this week, Reuters reported.

According to US Army General Mark Milley, chairman of the Joint Chiefs of Staff, a secure airport would be essential to ensuring that the United States and European allies could maintain embassies in Afghanistan.

“We are working out the details of how to secure the airport, how to support the Afghan military securing the airport, and what countries are willing to contribute to do that,” Milley told reporters shortly before landing in Washington after talks with NATO allies in Brussels.

President Joe Biden’s April order to pull out all troops by September 11 could inflame Afghanistan’s internal conflict between the internationally backed Afghan government and the Taliban insurgency, Reuters reported.

The Biden administration has stressed that the United States will remain committed to Afghanistan, shifting its focus to diplomacy while continuing robust financial support to Kabul.

But such diplomacy — including efforts to foster a so-far elusive peace agreement between Kabul and the Taliban — would suffer greatly if the United States and its European allies can’t keep embassies open because of security threats inside Afghanistan, reported Reuters

Milley said of the airport: “That is one of the keys to maintaining a diplomatic presence.”

He said NATO chiefs of defense discussed the issue in Brussels on Tuesday. But decisions about any security force deployments by individual countries for the airport would be made later by political leadership, he said.

Milley declined to speculate about the size of any international force at the airport.

“I think NATO and others are working that in various working groups to see what the exact number is going to be. Those numbers aren’t known right now,” he said.