A declaration of war huh!

This is an excerpt from CNN. "The U.N. Security Council slapped North Korea today with trade, travel and other sanctions as punishment for its claimed nuclear weapons test. North Korea's ambassador accused the council of being "gangster-like" and said further U.S. pressure would be seen as "a declaration of war" before he walked out of the chamber."

Please somebody tell the North Korean ambassador who's declaring the war! Is he out of his mind? If his big boss didn't make a stupid move such as violating the U.N. council and continuing the Nuke test, they shouldn't have been sanctioned.