The world of politics is so messed-up today! I wouldn't be surprised if the US is paying for North Korea to make these threats so they can continue their political goals in the east.
They are sending there food through the UN humanitarian aid channels. There is a thread somewhere around this forum where this issue is analyzed in greater detail.
Major powers (US & China included) are subsidizing DPRK with the
"humanitarian aid" made of food & fuels; however, due to Songun ( Army First) policy of the North Korean regime this allow the government to dedicate his scarse resources to Armed Forces benefit and to luxury goods for the ruling elite. Just as the humanitarian aid to Somalia in the 90s displaced local food producers (why someone need to buy food when he can get free from UN camps?) thus creating a real famine.