As you can understand Donald have more time for his president job, because Melania live currently in New York ( less family life means more time for work ), so he can also start to think some more strong reaction on North Korea nuclear weapons & missile programme ( see more info here -
http://www.bbc.com/news/world-asia-17399847. What can happen if he will do something against North Korea ? Do not forget US obligations and US army presence in South Korea.
He is sending a carrier task group to the area. Maybe a false flag is in order and a reason to go in and kill that dicktator once and for all. China maybe against it but who knows what kind of deal he struck with Xi Jinping. Maybe they agreed to divide up the north between themselves. No one is going to care what happens to the Kim family.