The 76-year-old leader was sworn in on Wednesday amid tight security in the Nigerian capital Abuja. He did not make a speech during the low-profile event attended by members of the diplomatic community.
Buhari, a former military ruler, won 56 percent of the votes to defeat his main challenger, former Vice President Atiku Abubakar of the Peoples’ Democratic Party (PDP) in the February election, which had been beset by a host of security and logistic issues that delayed the vote by a week.
Following the announcement of the election results, Abubakar filed a petition against the outcome, a process that is ongoing in Nigeria’s appellate court.
Buhari will face a number of challenges during his second term as he tries to fulfil his election promises, including dealing with security threats and managing a sluggish economy and a high unemployment rate.
Security remains a major challenge for Buhari after a first term marked by kidnappings, bandit attacks, cattle rustling and communal conflicts.
Babatunde Fashola, a former government minister, told Al Jazeera that Buhari has been entrusted with resolving the issues.
“[Insecurity] was a campaign issue on which the president has been re-elected, which shows the people’s trust in his ability to solve the problem,” Fashola said.
Buhari’s home state of Katsina witnessed an escalation in violence, with several villages raided by armed bandits, while the Boko Haram armed group continues to operate in the northeast of the country.
Persisting tensions in the northeast could escalate into more violence, according to Nnamdi Obasi, Nigeria researcher at the International Crisis Group.
“Boko Haram, now split into two factions, will continue its decade-long campaign to establish an Islamic state in the northeast, even as the herder-farmer violence has ebbed since the second half of 2018,” Obasi said.
In Nigeria’s fertile central region, herders and farmers continue to fight over land and water resources, the clashes between them claiming hundreds of lives and displacing thousands more.
Communities in the oil-producing Niger Delta – which accounts for most of the country’s foreign exchange reserves – have long complained of government neglect, leading to unrest in the region.
Armed groups have attacked oil installations in the past, halting production and kidnapping expatriate workers. Many of those fighters were brought under a government amnesty which entitles them to monthly stipends and education programmes.
In addition to the security situation, areas polluted by oil drilling activities have yet to be cleaned up, as a project to tackle that issue is yet to begin.
“In the Niger Delta, the continuing delay in addressing environmental grievances and diverse regional demands, coupled with possible termination of the decade-long amnesty programme, could lend room for opportunistic groups to resume sabotage of the petroleum industry,” Obasi said.
“Countrywide, massive youth employment, feeble policing and the deepening atmosphere of impunity, all suggest that kidnapping and other public safety situation could deteriorate further,” he added.
Nigeria’s unemployment rate has more than doubled to 23 percent since Buhari assumed office in 2015, while 90 million Nigerians are living in extreme poverty, more than than any other country, according to findings based on a projection by the World Poverty Clock and compiled by the Brookings Institution.
Nigeria is Africa’s largest economy and economic analysts say the next four years offer another opportunity to fix the problems.
“On the monetary policy side, they need to abandon their fixation on the exchange rate. The Central Bank of Nigeria is not ready to deal with any economic shocks at the moment because they have boxed themselves into a tight corner while trying to manage the exchange rate,” Nonso Obikili, an Abuja-based economist, told Al Jazeera.
“I think the economy will continue to grow around two percent over the next one or two years. That, of course, is very bad given our population growth, poverty, and jobs crisis,” Obikili said.
Buhari also faces the task of weeding out corruption, which has hurt the economy and the ease of doing business in the country.
According to Transparency International’s 2018 Corruption Perceptions Index, Nigeria failed to improve its ranking of 144th out of 180 countries from the previous year, despite “a number of positive steps” taken by the Buhari government.
However, the opposition has criticised Buhari’s record in the fight against corruption, a promise he ran on in his initial 2015 campaign.
“The fight against corruption has been an abysmal failure, to put it mildly. It turned from prosecution to persecution of perceived political foes,” Anthony Ehilebo, Head of Digital Media for the PDP’s presidential campaign team, told Al Jazeera.