He was greeted at Bissau airport by singing crowds, some holding placards which read “the son of the country is back”.
“Today, I have returned to embrace my brothers, my friends, to encourage them to find a way out of this crisis through dialogue,” he told supporters of the ruling African Party for the Independence of Guinea and Cape Verde (PAIGC).
“I believe that reconciliation is possible,” he said, telling reporters he had no intention of returning to politics.
In April 2012, the then prime minister Gomes Junior and his PAIGC government were overthrown in a coup led by the head of the influential army between the first and second rounds of a presidential election that he was expected to win.
On Sunday Prime Minister Umaro Sissoco Embalo submitted his resignation to the president, in a bid to end a two-year political crisis in the poor west African nation.
Guinea-Bissau has been in the throes of a power struggle since August 2015, when President Jose Mario Vaz sacked the then prime minister Domingos Simoes Pereira.
At its latest summit on December 16, the ECOWAS west African bloc urged Guinea-Bissau’s leaders to resolve the crisis marring their tiny nation within two months, or else face sanctions.
Vaz and former prime minister Pereira — who heads the ruling party — have accused each other of blocking the implementation of an accord reached in October 2016.
Guinea-Bissau, one of the world’s poorest countries, has been plagued by military coups and instability since its independence from Portugal in 1974.