An estimated 7.5 million were eligible to vote in Sunday’s elections.
“We expect Issoufou to be elected quite comfortably, probably even within the first round,” said Vincent Rouget, a security analyst who specialises in west Africa for the London-based consulting group Control Risks.
“He has a well-funded campaign with large media coverage and will benefit from large rural support that should allow him to be reelected quite comfortably.”
Issoufou’s 14 opponents include the controversial 66-year-old Hama Amadou, who is currently in jail for his alleged role in a baby-trafficking scandal. Niger's first ever democratically elected president Mahamane Ousmane is also running.
The opposition has accused Issoufou of attempting to rig the elections, stating there had been an issue with duplicate voter cards and missing ballots.
While more than 25,000 voting centres were made available throughout the country, many still persist fairness in reporting will be a large issue over the coming days.
“Civil society is mobilised in order to ensure the regularity of this vote but in Africa [fairness in reporting] is a big challenge shared by many countries,” said Florent Geel, head of the Africa Bureau at the International Federation for Human Rights.
If Issoufou does win Sunday’s election, one of his biggest challenges is expected to be maintaining national security.
“Facing a number of security challenges, he will have quite a lot of trouble maintaining stability within the next five years if he’s elected,” said Rouget.
Niger’s northern border has been threatened by a number of jihadists operating within Mali and Libya, while the south-east region continues to be faced with attacks from Boko Haram, displacing thousands.
Results of the first round of elections are expected to be counted within the next five days.