A spokesman for the Nigerian presidency said on Friday that the leaders of the Economic Community of West African States (ECOWAS) would make a "major decision" about the Gambia at the meeting scheduled for Saturday.
The Gambia's long-time President Yahya Jammeh says he will not step down despite losing the December 1 presidential election to Adama Barrow.
Last month, ECOWAS leaders said they would do anything necessary to uphold the result of the election in the Gambia.
ECOWAS then placed its military forces on standby to intervene in case Jammeh attempted to stay in power after his mandate ends on January 19.
Jammeh has called the ECOWAS move "a declaration of war," and said he will defend himself against possible military intervention.
Jammed says ECOWAS has no right to interfere in the internal affairs of the Gambia, and that the outcome of the election should be determined by the Supreme Court, where he has lodged a complaint.
Garba Shehu, a spokesman for Nigeria's President Muhammadu Buhari, emphasized the importance of the meeting in Ghana.
"A major decision on the impasse is expected to be taken at that all-important meeting," said Shehu, adding that the Nigerian president was adamant to end the crisis in the Gambia.
"President Buhari is the chief mediator of the crisis, and he is committed to ensuring that the logjam is resolved," he said.
After the election in the Gambia, President Jammeh initially accepted losing to Barrow, triggering nationwide celebrations on the streets.
However, a week later, he changed his mind, saying the electoral commission had been biased toward his rival.
He, then, filed a complaint with the Supreme Court against the electoral commission and vowed to remain in office despite regional and international pressure to concede defeat.
Jammeh has ruled the Gambia for more than 22 years.