In a pattern that goes back to the cease fire negotiations during the 1950-53 Korean War, North Korea is making impossible demands and outrageous statements before getting down to serious negotiations. Remember, during the Korean War negotiations, the North Koreans would argue and posture for weeks over things like the placement of tables in the negotiating room. What the North Koreans want is money, or things like food and fuel to keep their failed economy going. North Korea needs cash, though, to maintain it's police state. At the moment, food donors are holding back after constant refusals by the North Koreans to allow UN aid workers to confirm that food was getting to starving people. Reports from the other side of the North Korean borders in Russia and China indicate that donated food is being secretly exported to raise cash, or added to military stockpiles. At the moment, fuel shipments are halted, food shipments are less than half of what is needed and South Korean investments in the northern economy have slowed down. Things are not looking good for the band of despots desperately hanging on to power in the north. These guys need money, food and fuel to survive and are willing to starve their own people and threaten devastation to their neighbors to get what they need.
The US has said it is willing to talk to North Korea, but not give in to their demands for aid without getting verifiable cancellation of North Korean missile and nuclear programs. South Korea is willing to pay off the northerners, believing that increased business investment in the north will eventually turn things around. Japan is less optimistic and the Japanese are considering increasing their military and building nuclear weapons.