WASHINGTON - US Strategic Command said on Thursday it had tracked two attempted missile launches by North Korea since Wednesday evening, neither of which posed a threat to North America.Army Lieutenant Colonel Martin O'Donnell, a STRATCOM spokesman, said Strategic Command detected and tracked "what we assess were attempted North Korean missile launches at 4:43 p.m. US central daylight time (2143 GMT) on Wednesday and at 5:24 a.m. central daylight time (1024 GMT) on Thursday."The North American Aerospace Defense Command (NORAD) determined the missiles launched from North Korea did not pose a threat to North America," O'Donnell said in a statement.