A powerful security adviser to President Goodluck Jonathan has resigned from his post, saying he will seek the presidency himself in Nigeria's coming election. A spokesman says National Security Adviser Aliyu Gusau resigned his position on Friday. Spokesman Adekunle Adebisi says Gusau will apply Monday to the ruling People's Democratic Party to run as a candidate in the October primaries. Gusau, a retired Army general, is a powerful, behind-the-scenes player in Nigeria's military and security agencies. He served as national security adviser to Nigeria's two past presidents. He also ran in the 2007 presidential primary before bowing out. Jonathan became president after the death of Nigeria's elected leader in May and formally launched his campaign Saturday. 