The “Songun” referred to in the declaration means a concentration on the importance of arms in socialist revolution.
Full war declaration statement from DPRK (via KCNA):
The moves of the U.S. imperialists to violate the sovereignty of the DPRK and encroach upon its supreme interests have entered an extremely grave phase. Under this situation, the dear respected Marshal Kim Jong Un, brilliant commander of Mt. Paektu, convened an urgent operation meeting on the performance of duty of the Strategic Rocket Force of the Korean People’s Army for firepower strike and finally examined and ratified a plan for firepower strike.
The important decision made by him is the declaration of a do-or-die battle to provide an epochal occasion for putting an end to the history of the long-standing showdown with the U.S. and opening a new era. It is also a last warning of justice served to the U.S., south Korean group and other anti-reunification hostile forces. The decision reflects the strong will of the army and people of the DPRK to annihilate the enemies.
Now the heroic service personnel and all other people of the DPRK are full of surging anger at the U.S. imperialists’ reckless war provocation moves, and the strong will to turn out as one in the death-defying battle with the enemies and achieve a final victory of the great war for national reunification true to the important decision made by Kim Jong Un.
The Supreme Command of the KPA in its previous statement solemnly declared at home and abroad the will of the army and people of the DPRK to take decisive military counteraction to defend the sovereignty of the country and the dignity of its supreme leadership as regards the war moves of the U.S. and south Korean puppets that have reached the most extreme phase.