General Brice Oligui Nguema, who came to power in a coup last August, met Ivory Coast's President Alassane Ouattara during a visit to the country for "work and friendship" from Thursday to Saturday.
"I am asking for the support of my elder here to plead in favor of lifting of the African Union sanctions against Gabon, and I know I can count on you," the general said, addressing the Ivorian president.
Gabon was suspended from the African Union on August 31 after Nguema overthrew president Ali Bongo, whose family had been in power for 55 years.
He pledged to hand back the oil-rich central African country to civilian rule after a two-year transitional period.
The Economic Community of Central African States (ECCAS), which had also suspended Gabon over the coup, reinstated it in March.
Thursday's meeting came after Gabon earlier this month launched a national dialogue intended to pave the way for elections in 2025.
In a joint statement to the press, the general said that he had given Ouattara an "update and report" on the "progress of the current dialogue in Libreville."
He also thanked Ouattara for his "involvement" and "constant willingness to support and accompany the transition process on Gabonese soil."
For his part, Ouattara told reporters that the meeting led to "fruitful exchanges."
Ouattara praised Nguema for "the efforts you are making to return to constitutional normality" and for convening an "inclusive national dialogue."
Gabon's transitional president also plans to hold talks with the Gabonese diaspora during his visit.