The Buhari administration is committed to freeing Leah Sharibu and is in negotiation with the kidnappers to do so, a presidential aide said on Saturday.
Garba Shehu said the Buhari administration will not give up on the safe return of Miss Sharibu.
Miss Sharibu is one of the 110 students of Government Girls Science and Technical Secondary School, Dapchi, who were kidnapped by Boko Haram terrorists in February 2018.
About four of the girls died during the kidnap while the terrorists released the other 105. They, however, held on to Miss Sharibu, reportedly for holding on to her Christian faith.
However, several rights activists and groups have demanded that the federal government should secure the release of the teenager.
In a statement issued on Saturday, Mr Shehu addressed a group of journalists saying; "Instead of giving up, the government is carrying forward processes that should hopefully yield her release by her captors."
The spokesperson claimed to be responding to the "worrying cycle of speculations on whether Leah Sharibu, the kidnapped Dapchi schoolgirl, had been harmed by her abductors."
He noted that the government is still in communication with the abductors to negotiate her release.
"Lines of communications remain open with the kidnappers, ISWA, to secure the release of Leah Sharibu.
The spokesperson said Ms Sharibu "is alive - given assurances from our security agencies-, and the government is committed to her safe return, as well as all other hostages to their families."
Mr Shehu then suggested that while the government was negotiating with the terrorists, it was unwilling to pay a ransom, an act he said should be discouraged.
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"Kidnapping for ransom should never be encouraged. This means not capitulating to the demands of terrorists: refrain from rewarding their heinous crimes with payment.
"With the abduction of loved family and friends, the government understands how difficult these time are for them, but government is pursuing many options to ensure the safe return of Leah Sharibu.
"We must commit to law and communication, using the breadth of strategies at our disposal: legal initiatives, stakeholder cooperation, involvement of all relevant parties and the use of the latest hostage negotiation techniques.
"Kidnapping for ransom is rising across the Sahel. We must - collectively - make sure we implement best practice to prevent its exploitation," he said.
Mr Shehu appealed to Nigerians to be patient. He assured that the administration is fully conscious that any misstep on a delicate issue as this can be costly.