President Donald Trump on Wednesday directed the Defense Department and the Department of Homeland Security to prepare the naval base at Guantanamo Bay to hold up to 30,000 immigrants awaiting deportation from the U.S.

ABC News’ Phil Lipof on Wednesday spoke with Karen Greenberg, director of the Center on National Security at Fordham University School of Law, to discuss the plan for the military base in Cuba.

ABC NEWS: The director of the Center on National Security at Fordham Law School, Karen Greenberg. Karen, thanks for being with us. We are talking about an American military base on foreign soil. What does that mean for immigrants’ access to due process?

KAREN GREENBERG: OK, so first, it’s not really foreign soil in the United States’ terms — it’s an outpost of the United States. And that’s always been one of the confusing things about Guantanamo.

What it is is a place where, repeatedly, the United States has sought to place individuals without the kinds of protections by law that they have in the United States on the homeland, as we’ve seen with the detention of war on terror detainees. And also, you know, we can talk about the migration center as well, but it is not correct to call it on foreign soil. It is on a U.S. base located in Guantanamo Bay.

ABC NEWS: All right, so you’ve been to that facility where they’d be held at Guantanamo Bay. What challenges will the administration face in trying to implement the plan?

GREENBERG: So one big challenge that they’re going to face is basically the numbers he was throwing around. He threw out 30,000 — I don’t know that they have the capacity for that, but I have never heard that before. At the height that I knew about it, in the old days and the ’90s, I think they held 21,000 at the most.

They’ve held refugees repeatedly. In current context, President Biden talked about using it for migrants as well, but never, and we’re using it now for some intercepted asylum seekers and migrants. But that kind of capacity, that kind of number, hasn’t been thrown around before.

So I’m assuming that will mean they will need to build up some kind of facility, not just for the numbers they’re talking about in terms of migrants, but also for the guards, the health facilities, etc., etc., that we’ll need there.

And just to make a point there, they had to build Guantanamo detention facility, also, you know, for the war on terror detainees. And they did that very rapidly. They did it within 100 days, and built, you know, state-of-the-art maximum security prisons and housing for those who would need to attend to them. So it can be done quickly.

ABC NEWS: As you point out, the base has been used to hold much smaller numbers of immigrants for years. What could some of their experiences tell us about Guantanamo?

GREENBERG: Well, the reports are not good. And I want to say that it’s not just the past reports that are not good. It’s also, there was a report released in September by the International Refugee Assistance Project, which sort of detailed the conditions that migrants are held in currently at Guantanamo, which included unsanitary conditions, mistreatment, not to mention this sort of fuzzy legal status.

So I don’t think that’s projected well in the past, there’s also been in these prior times, in the ’70s and the ’90s also, you know, allegations of, and documents of mistreatment and unsanitary conditions, etc.

ABC NEWS: Certainly a lot to work out moving forward. Karen Greenberg, thank you.