Good news: North Korea is getting increasingly angry at the Trump administration. Leader Kim Jong Un is feeling increasing pressure and knows he'll soon have to decide whether to disarm himself of his nuclear weapons or face new pressure.

Still, there's no question that North Korea is increasingly unhappy. Its state media has spent the past day or so attacking Trump's team (though not the president himself) for "expecting any result, while insulting the dialogue partner." This, it described in characteristically odd terms, was a "foolish act that amounts to waiting to see a boiled egg hatch out."

Yet what's going on here is quite simple. North Korea is aggravated by two factors.

First, the increasing U.S. pressure on China and Russia to stop weakening their enforcement of United Nations-authorized sanctions on Pyongyang. New sanctions on Russian financial outlets doing business with Pyongyang have raised alarm bells in both that capital and Moscow.

Second, North Korea is upset over demands from Secretary of State Mike Pompeo that it begin identifying and dismantling its nuclear and ballistic missile production sites. Until now, the North Koreans have only taken very limited steps to dismantle these sites. More concerning, North Korea continues with its late-stage development of a nuclear intercontinental ballistic missile capability in the area of warhead re-entry vehicles and redundant nuclear strike capabilities.

Fortunately, the Trump administration has rightly recognized that no positive diplomatic breakthrough can occur if these activities continue. Albeit behind close doors, Pompeo is telling the North Koreans that they must take tangible action soon or face new U.S. sanctions and military pressure. This alarms Kim, in that while he desperately wants sanctions relief, he also knows the U.S. has the capability to impose a solution upon him (trust me, it does). Kim also knows that Trump's summit diplomacy has earned the U.S. president more allied support if he ever decides to use force.

Put simply, North Korea's new anger reflects the fact that the U.S. is wresting back the initiative here. That's a good thing.