Trump has brought back up the issue that South Korea should pay more for defense from U.S. troops however with the cost sharing deal recently concluded that extends to 2030, this seems like campaign rhetoric at this point. Trump is once again using a lot of hyperbole to make his greater point that allies should pay more for international security provided by U.S. troops:

Former President Donald Trump said Wednesday that America “cannot be taken advantage of any longer in trade and in the military,” reinforcing speculation that he could demand renegotiation of a recent defense cost-sharing deal with Seoul if he returns to office.
The Republican presidential candidate made the remarks during a televised town hall event hosted by Fox News, falsely claiming that South Korea does not pay for the stationing of the 28,500-strong U.S. Forces Korea (USFK).
“40,000 soldiers and we never get paid. South Korea, they don’t pay,” Trump said, apparently referring to 28,500 USFK service members.
“I made them pay. Everyone raised hell, and Biden took the deal, and he said they don’t pay anymore, and they’re a rich country. No … we have to start. We cannot be taken advantage of any longer in trade, in the military,” he added.
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