The US is demanding North Korea deliver them a full list of all locations of their nuclear arms at an upcoming summit. There is still no date for the summit, and indications are it is being delayed. North Korea is expressing frustration at the US approach to talks, centering entirely on threats.
South Korea has a major interest in seeing US-North Korea talks successful, and while reluctant to publicly criticize the US, they are quietly pushing the US to do something about the lack of confidence, saying they need to build trust with the north.
Inter-Korean diplomacy seems a good example of this, with both sides making a number of measures back and forth building confidence, and making tremendous progress. The Trump Administration has so far refused to take any actio until North Korea fully disarms its nuclear program.
North Korea is increasingly suspicious of a plan wherein they’d be unilaterally giving the US everything they want for years on end in the hope of the US granting them peace at the end, when they’re no longer able to defend themselves.
And the fact that North Korean state media is expressing reticence about this plan has US officials threatening more sanctions and measures against them. South Korean officials warn the two could be trapped in this cycle forever unless the US is willing to make at least some steps toward improving the process.