From the NYTimes - Trump Gushes...
What if this whole "summit" was orchestrated before hand by Russia, NK, and the dumpster administration and they decided they would undo the results of the Korean War (conflict, that is) - since Russia backed North Korea then - and just give the South to Kim Jung Un? Yes, that is a wild conspiracy theory but look at what they have done already from before the election until now. They (including the GOP domestically, BTW) are working to undo anything that was instituted since WWII.
The term security guarantees was not explained, but in providing them to allies like South Korea and Japan, the United States has committed to use military force to come to their defense. It seems highly unlikely that would apply in the case of North Korea, and it shouldnt.
Mr. Trump later told a news conference that he still hoped at some point to withdraw the 28,500 American troops from that country. He said he intended to halt American war games held routinely with South Korea because they are expensive and provocative.
But it seems that he failed to forewarn both the Pentagon and President Moon Jae-in of South Korea, a grievous mistake, especially with an ally who is directly affected by the decision and played a central role in causing the Kim-Trump meeting to happen. While Mr. Moon hailed the meetings outcome in general, stunned South Korean officials worried that Mr. Trump was making concessions too fast. The South Korean Defense Ministry said it was seeking to clarify the presidents intentions.
[link:
https://www.nytimes.com/2018/06/12/opinion/trump-north-korea-summit-nuclear.html?action=click&pgtype=Homepage&clickSource=story-heading&module=opinion-c-col-left-region®ion=opinion-c-col-left-region&WT.nav=opinion-c-col-left-region|]