Nigeria’s president, Muhammadu Buhari, is prepared to swap Boko Haram prisoners for the Chibok schoolgirls, a minister has said.

Last year the government almost secured the release of the girls whose kidnapping triggered global outrage, but three times the negotiations collapsed. On the first occasion, in August, Buhari had agreed to the prisoner swap and the militants were taken to Maiduguri, the city Boko Haram regards as its spiritual home.

“All things were in place for the swap which was mutually agreed,” Lai Mohammed, the information minister, said in a statement. “Expectations were high. Unfortunately, after more than two weeks of negotiation and bargains, the group, just at the dying moments, issued a new set of demands never bargained for or discussed by the group before the movement to Maiduguri. All this while, the security agencies waited patiently. This development stalled what would have been the first release process of the Chibok girls.”

The recent battle for the leadership of the group that has murdered, raped and kidnapped thousands of people and displaced millions has been a major setback in negotiations, he said. Islamic State, of which Boko Haram is an affiliate, announced last month that Abu Musab al-Barnawi was its new leader, replacing Abubakar Shekau – something analysts say may have been a reaction to the many Muslims murdered under his tenure.

However Shekau later claimed still to be in control of the group and a video released of the Chibok girls seemed to have come from his camp. “The current division among members of the terrorist group ... has seriously affected efforts to release the girls,” Mohammed said.

In an interview with the Guardian, Mohammed said that the government was now sure it was negotiating with the right people. The previous government under Goodluck Jonathan conducted high-level negotiations before realising that they were talking to charlatans.

Muhammadu Buhari greets the child of one of the Chibok girls rescued after two years in captivity with Boko Haram. Photograph: Afolabi Sotunde/Reuters

“We are confident that we have a grasp of the divisions in the group, so when there have been setbacks in the negotiations we have known why,” he said. “We can’t put any sort of time on [their release]. The thing is we are dealing with a group that can change the goalposts at any time. It is and has been a really tricky situation,” Mohammed said.

He added that negotiations under Jonathan did not start until a year after the 276 girls were captured from a school in Chibok, north-east Nigeria, making it more difficult for Buhari. “It’s been a very testy matter because these divisions in Boko Haram are constantly shifting. But we inherited this situation and we are concentrating on rescuing the girls.”

Buhari’s government was thought to be attempting to rescue the girls. The army had launched air strikes on Boko Haram strongholds and claimed to have wounded its leader.

The Bring Back Our Girls group, which has long campaigned for their release, welcomed the news. “Our movement has been asking for feedback on our government’s rescue efforts since our last meeting of 14 January 2016,” said Oby Ezekwisili, founder of the moment. “So we consider this briefing by the federal government a start. We welcome every factual communication of their effort to bring back our girls and hope that this signals a new period of continuous feedback to parents, our movement and the general public.”

Not all parents were so optimistic, however. “I don’t believe the government is making any efforts to rescue our girls,” said Yakub Bulus, the father of one of the Chibok girls. “I will only believe it when I see our girls. Since 2014, when our girls were taken, it has been the same promises and assurance without results, so what the minister says is not true, they are not doing anything.”

His wife, Esther, dismissed Mohammed’s claim as “the usual lies” that the government was working to bring back their daughters. “The last time they were here they gave out money to parents of school kids who have being attacked or taken by Boko Haram. I don’t need money, all I need is my daughter.”

The Chibok girls represent just a fraction of the thousands of abductees – of all ages and genders – that Boko Haram has taken since its rise in 2009. In areas of northern Nigeria that the army wrested back from the terrorist group, millions of victims of malnutrition, neglect and in some cases famine are surfacing, presenting a humanitarian crisis on a scale that humanitarian workers are warning has never been seen before.