North Korea has protested against criticism of its latest satellite launch by the U.N. and NATO chiefs, calling its military reconnaissance program a legitimate “self-defense” measure against threats from the U.S. and its allies.

U.N. Secretary-General Antonio Guterres and NATO Secretary General Jens Stoltenberg condemned North Korea’s failed attempt on Wednesday to place a military spy satellite into orbit using ballistic missile technology, labeling it a sanctions violation and security threat in separate statements.