The only signal sent to NK is that we had a president who was apparently born with his brain up his ass and sh*t it out followed by one who is disinclined to continue with an absolutely worthless nonbinding agreement.
Trump had the wisdom to see that the Iran deal was more or less the exact same kind of garbage deal that Clinton made with NK in the 90's and we can see where that went.
Sadly though, I think our previous America-hating President knew exactly where the deal would lead when he made it.