Lagos , Nigeria ( CNN ) A day after winning Nigeria 's presidency , Muhammadu Buhari told CNN 's Christiane Amanpour that he plans to aggressively fight corruption that has long plagued Nigeria and go after the root of the nation 's unrest . Buhari said he 'll `` rapidly give attention '' to curbing violence in the northeast part of Nigeria , where the terrorist group Boko Haram operates . By cooperating with neighboring nations Chad , Cameroon and Niger , he said his administration is confident it will be able to thwart criminals and others contributing to Nigeria 's instability . For the first time in Nigeria 's history , the opposition defeated the ruling party in democratic elections . Buhari defeated incumbent Goodluck Jonathan by about 2 million votes , according to Nigeria 's Independent National Electoral Commission . The win comes after a long history of military rule , coups and botched attempts at democracy in Africa 's most populous nation . In an exclusive live interview from Abuja , Buhari told Amanpour he was not concerned about reconciling the nation after a divisive campaign . He said now that he has been elected he will turn his focus to Boko Haram and `` plug holes '' in the `` corruption infrastructure '' in the country . `` A new day and a new Nigeria are upon us , '' Buhari said after his win Tuesday . `` The victory is yours , and the glory is that of our nation . '' Earlier , Jonathan phoned Buhari to concede defeat . The outgoing president also offered a written statement to his nation . `` I thank all Nigerians once again for the great opportunity I was given to lead this country , and assure you that I will continue to do my best at the helm of national affairs until the end of my tenure , '' Jonathan said . `` I promised the country free and fair elections . I have kept my word . '' Buhari , 72 , will be sworn in on May 29 . He will take the helm at a critical time , as Nigeria grapples with Boko Haram , serious economic woes and corruption . This is n't Buhari 's first time leading Nigeria , but it 's his first time in nearly 30 years . A military coup brought Buhari to power in late 1983 , closing a brief period of popular rule by Shehu Shagari . But Buhari himself was ousted by another military coup in August 1985 . Read more : Who is Nigeria 's Muhammadu Buhari ? His presidential win is the result of his fourth attempt to lead the country since he was ousted 30 years ago . Buhari is a Sunni Muslim from Nigeria 's poorer North , while Jonathan comes from a Christian and animist South that is rich with oil . Buhari praised voters for exercising their right peacefully . `` Your vote affirms that you believe Nigeria 's future can be better than what it is today , '' he said in his statement . `` You voted for change , and now change has come . '' Buhari campaigned as a born-again democrat to allay fears about his strict military regime . He stressed that Nigeria 's security needs to be the next government 's focus . His campaign was also fiercely anti-corruption . He ran under the slogan of `` new broom , '' and his supporters were often pictured holding brooms in the lead-up to the vote . Despite years of democracy , analysts say , corruption has hindered Nigeria from building a stable economy . One of Buhari 's biggest challenges will be Boko Haram , which has been terrorizing Nigeria as it tries to institute a strict version of Sharia law in the country . In the past few years , the terror group has bombed churches and mosques , killed hundreds of people and kidnapped more than 200 teenage girls from a boarding school . Even the presidential vote had to be postponed because of the radical militants . The election was originally scheduled for February 14 , but was delayed six weeks because the military needed more time to secure areas controlled by Boko Haram . Yet the violence persisted . On Saturday , residents in the northeastern state of Gombe said at least 11 people were killed in attacks at polling stations , apparently by Boko Haram extremists . Jonathan had been criticized for not doing enough to combat Boko Haram . Before the election , African affairs analyst Ayo Johnson said the vote would come down to who could make Nigeria feel safe . `` Many Nigerians will not forget ( Buhari ) was a military leader during a dictatorship , '' Johnson said . `` Or maybe they will feel that they need a military leader to address fundamental problems such as terrorism . '' Boko Haram is n't the only obstacle facing the new president . The economy is another major issue . Nigeria overtook South Africa last year as the region 's largest economy . Nigeria is one of Africa 's largest oil producers and is a major supplier of crude oil to the United States . It also hosts many international oil companies and workers . But many complain that the country 's vast wealth from oil exports does n't trickle down to the average citizen . As many as 70 % of Nigerians live below the poverty line , surviving on less than a dollar a day . Christian Purefoy reported from Lagos ; Holly Yan reported and wrote from Atlanta . CNN 's Stephanie Busari , Faith Karimi and Susannah Cullinane contributed to this report .
Muhammadu Buhari tells Nigeria 's Christiane Amanpour that he will fight corruption in CNN . CNN is the most populous country in Africa and is grappling with violent Boko Haram extremists . CNN is also Africa 's biggest economy , but up to 70 % of CNNns live on less than a dollar a day .