Republican presidential nominee and former U.S. President Donald Trump speaks as he is interviewed by Bloomberg Editor-in-Chief John Micklethwait at the Economic Club of Chicago in Chicago, Ill., U.S. Oct. 15. Reuters-Yonhap

Former U.S. President Donald Trump said Tuesday that South Korea would be paying $10 billion a year for the stationing of the 28,500-strong U.S. Forces Korea (USFK) if he was in the White House, as he described the Asian ally as a "money machine."

The Republican presidential candidate made the remarks as Seoul and Washington recently concluded their negotiations over a defense cost-sharing deal, called the Special Measures Agreement (SMA), which will last through 2030.

"If I were there now, they'd be paying us $10 billion a year. And you know what? They'd be happy to do it," he said during an interview with the Economic Club of Chicago and Bloomberg News in Chicago. "It's a money machine. South Korea."

Trump also touched on the tough SMA negotiation process with South Korea when he was in office, confirming he demanded South Korea pay $5 billion a year at the time.

"We have 40,000 troops in harm's way, very serious, because you have North Korea's very serious power. They have tremendous nuclear power," he said, referring to 28,500 USFK personnel. "I said to South Korea, 'You're going to pay,' and they agreed to do it, and Biden then cut it back. And it's a shame."

Earlier this month, South Korea and the U.S. reached the 12th SMA to determine Seoul's share of the cost for the upkeep of USFK. Under the deal, Seoul is to pay 1.52 trillion won ($1.14 billion) in 2026, up from 1.4 trillion won in 2025. The deal links an annual increase in Seoul's SMA contributions to the Consumer Price Index.

Seoul and Washington launched their SMA negotiations in April — earlier than usual — amid concerns that Trump could drive a hard bargain over burden sharing in a way that could cause tensions in the bilateral alliance amid growing North Korean military threats.

Despite the conclusion of the negotiations, concerns have surfaced that should Trump be elected in November, he could demand renegotiation of the deal.

Since 1991, Seoul has partially shouldered costs under the SMA for Korean USFK workers, the construction of military facilities and other logistical support. (Yonhap)