President Trump explained why American troops are still in Afghanistan after almost 20 years of conflict during an interview that aired Monday on Tucker Carlson Tonight.

"Well, I'll tell you," Trump explained. "I've wanted to pull them out. And you know, I have pulled a lot out. We were at 16,000. We're down to about 9,000, which a lot of people don't know. In Syria, as you know, I've pulled most of them out."

Trump said because the country has been involved in the Middle East for so long, we have a become the "police" for the world and other countries. Other countries such as Russia and China, he said, don't try to police the world.

Carlson asked if it was possible to completely withdraw from the war-torn region.

"I'll tell you the problem is. Look, I would like to just get out. The problem is, it just seems to be a lab for terrorists. It seems — I call it the 'Harvard of terrorists,'" Trump said. "When you look at the World Trade Center, they were trained. They didn't — by the way, they attacked the wrong country. They didn't come from Iraq, all right. They came from various other countries. But they all formed in Afghanistan, and it's probably because it's at the base of so many countries, but they all formed and it's rough mountains and you get a lot of — you know, you get a lot of good hiding places."

Trump said people in the military have told him they would rather fight terrorists on their home turf than in the U.S.

"Now, I would leave and will leave — we will be leaving. Very strong Intelligence, far more than you would normally think because it's very important, and we can do it that way, too. But we have reduced the forces very substantially in Afghanistan," he said.

Master Sgt. Michael Riley, 32, of Heilbronn, Germany, and Sgt. James Johnston, 24, of Trumansburg, New York, were killed last Wednesday during a firefight in Uruzgan Province, bringing the total number of U.S. service members killed this year in Afghanistan to 10.