It has not been officially reported by the North Korean govt, but long running rumors are now being reported by various serious media that Trump's big pal Kim Jong Un has recently killed the top 5 officials of his govt who set up his failed summit with US President Trump.
According to sources I watch there has been a massive crop failure this year in the Democratic Peoples' Republic (DPRK). The big issue there is if the local, semi-allowed private markets in ag will save the population from outright starvation. At this time this is not known.
So this difficult situation may be partly responsible for Kim Jong Un killing the top five negotiators with the US on nuclear weapons for the summit in Hanoi. In addition, reportedly five more senior officials have been sent to rural labor, or something like that.
A report from South Korea's Chousn Ilbo nuwspaper is that whom Kim Jong Il killed was Kim Hyok Choi, along with four others, although this has not been confirmed by outside observers. The newspaper also claimed that five other officials were sent to hard labor, but at least one of those has appeared in public, so this raises questions about this report, which some doubt (see comments below)
The unclear question is how much will the unofficial private markets in DPRK will save people from outright starvation/famine. The deepest sources ai have followed say that it is unclear. DPKR is not a "normal" country, and we have no way to know what is actually going on there now.
Given that his nation is facing food shortages, it is not surprising that he may be facing an internal challenge, and now we see that manifested by him overcoming any inside opposition by killing these five individuals.
Note that this post has been revised in light of new information and comments below.