Nigerian President Goodluck Jonathan's office confirmed on Wednesday that he will seek a second term in office in elections set for February.
Jonathan, who had been widely expected to run again, will collect a nomination form on Thursday to be the ruling party candidate in the presidential vote, his spokesman said.
"President Jonathan thanks all Nigerians, members of the PDP, friends, associates who in sincere appreciation of the achievements of the administration in the last four years have been urging him to seek a second term in office," presidential spokesman Reuben Abati said in a statement emailed to press.
The announcement will be seen as a mere formality by the Nigerian political class since Jonathan had already been adopted as sole candidate by the board of the ruling People's Democratic Party (PDP).
Jonathan's government has been beset by criticism over its inability to end an insurgency by Boko Haram Islamists, for his response to their abduction of more than 200 schoolgirls still being held six months later, and for a raft of oil corruption scandals.
However, the president still appears to be in a strong position, partly because there is no clear alternative, but also because Nigerian elections tend to be fought more on vast patronage than on policy, which gives an encumbent in this oil-rich state an advantage.
The battle lines between Jonathan and whoever wins the nomination for the opposition All Progressives Congress (APC) are increasingly being drawn, with several defections both ways over the past year.
Nigeria's lower house speaker and fourth most powerful person, Aminu Tambuwal, defected to the opposition coalition on Tuesday, boosting its bid to unseat Jonathan.
The top two contenders for the APC presidential ticket next year are former military ruler Muhammadu Buhari and recently defected vice president Atiku Abubakar. Both are Muslim northerners, while Jonathan is a Christian southerner, which will inevitably add an ethnic and sectarian dimension to the contest.
In 2011 Buhari's defeat against Jonathan triggered three days of bloodshed that left 800 dead and 65,000 displaced.
The APC's failure to agree on a leader has diminished its support among Nigeria's elite and made it look weaker as the polls approach.
Several lawmakers defected to the APC last December as it gained momentum, but since then a number of powerful figures have swung back to the president's camp.