The Chibok schoolgirls were taken during the night last April.
Mr Buhari took power in July 2015 on the promise of defeating the Islamist extremist group within 18 months of him taking office.
The Daily Telegraph says the authorities were talking to the "few" fighters that have been jailed to see if they may be able to be used as bargaining chips in an exchange.
The Nigerian president suggested the "complete number" of kidnapped girls would have to be safely released in "reasonably healthy condition".
The news comes as the Nigerian military says it has rescued at least a dozen women and children from Boko Haram.
According to military spokesperson Colonel Sani Kukasheka Usman, they were freed earlier in the week when the army cleared Boko Haram camps in Borno state, in the northeast of the country.
There has not yet been any information on who the women and children were, where they were taken from, or what condition they were in, according to Christian Today.
So far in 2015 hundreds of hostages have been freed from Boko Haram, but none of the 219 Chibok school girls have been found.
Boko Haram has used women in the past to commit suicide bombings in Chad, Cameroon, Niger and Nigeria.
It is thought that since Mr Buhari's election, Boko Haram has killed more than 1,000 people and around 2.1 million have fled their homes.
