SPARKS, Nev. -- In his final campaign event here before Nevada's caucuses open, Donald Trump promised to keep open the military detention center in Guantanamo Bay, Cuba, then riffed on ways that he could do it on the cheap.

"This morning I watched President Obama talking about Gitmo," said Trump. "Guantanamo Bay -- which by the way, we are keeping open! And we're going to load it up with some bad dudes. We're going to load it up."

When the crowd inside the Nugget casino stopped cheering, Trump mused about one of the Obama administration's reasons for trying to shut the prison down.

"Here's the thing I didn't understand," he said. "We spend $40 million a month on maintaining this place? Now, think of it -- $40 million a month! What do we have left in there, like, a hundred people, or something? And we're spending $40 million? I would guarantee you I could do it for a tiny, tiny fraction. I don't mean $39 million. I mean maybe $5 million, maybe $3 million. Maybe, like, peanuts."

He continued: "Maybe in our deal with Cuba, we get them to take it over and reimburse us, because we're probably paying rent. We're going to keep it open, but we're going to get the cost down, because that's ridiculous."

In fact, the United States does not pay Cuba anything to operate the Guantanamo Bay base. Cuba leased the location to the United States in 1903, but after Fidel Castro took power, the Communist government of Cuba accepted the annual $4,085 payment just once. Afterward, it began a multi-decade stalemate, cutting off water to the base and refusing to cash the rent checks, which are written out by rote every year.

In Nevada and elsewhere, Trump is competing for the Republican nomination against two sons of Cuban refugees, Sens. Ted Cruz (Tex.) and Marco Rubio (Fla.). Earlier Tuesday, at a rally 30 minutes away from Sparks, Cruz warned (without evidence) that President Obama might hand the naval base over to Cuba as a "parting gift" or part of a larger deal.