Banjul - Gambia's Yahya Jammeh faced a "last chance saloon" deadline to step down as troops from five African nations stood by for action and key regional leaders flew in to make a final plea.
Mauritania's Mohamed Ould Abdel Aziz and Guinea's Alpha Conde told reporters hope remained for a political resolution to the country's handover crisis as they left for Banjul from Nouakchott, the Mauritanian capital.
"We still have every chance for a peaceful solution," Aziz said. "We have every interest in achieving that, we have enough conflicts in Africa going on without adding another."
Conde said a political solution "must be found" before boarding their flight.
The pair were due in Banjul as troops already inside The Gambia postponed military intervention to give Jammeh, who was defeated in elections last month, a final chance to leave the presidency and the country quietly.
A previously announced noon (12:00 GMT) deadline was expected to be extended to give the two leaders, who took off for Banjul after 1100 GMT, enough time to meet Jammeh.
The pair are long-term allies of the Gambian strongman, who has had more prickly relations with other west African leaders during the post-election crisis these last weeks.
Diplomats in Banjul had confirmed the last-ditch peace push, with one describing a "last chance saloon" moment before foreign troops led by Senegal remove Jammeh by force.
Jammeh has rejected President Adama Barrow's December 1 election win, despite significant pressure from regional powers and the UN, sparking a major crisis and sending tourists - vital for the tiny country's economy - fleeing.
In Conakry, minister and Conde advisor Kiridi Bangoura said Jammeh would be offered asylum in the country of his choice.
Barrow, who was sworn in at The Gambia's embassy in Dakar on Thursday, remained in Senegal awaiting the outcome of the talks, with hopes of taking over the reins of state from Jammeh as soon as his safety could be guaranteed.
He hailed a "victory of the Gambian nation" and demanded loyalty from his armed forces at his inauguration.
An imminent military operation was suspended late on Thursday to allow a final diplomatic push to convince Jammeh, who has ruled the former British colony since seizing power in a 1994 coup, to leave the country.
"We have suspended operations and given him an ultimatum," said Marcel Alain de Souza, head of the 15-nation Economic Community of West African States (Ecowas).
"If by midday, he doesn't agree to leave The Gambia... we really will intervene militarily," he added, but this looked likely to lapse with Aziz and Conde's late arrival.
As white flags reportedly flew from Gambian army posts in the countryside, tectonic shifts were said to be underway among the military elite, pointing to a gradual acceptance of Barrow, even among units known for loyalty to Jammeh.
A diplomatic source said a faction had "switched sides" among the elite Republican Guards who assure Jammeh's personal protection, following meetings among themselves at their Bakau barracks close to Banjul.
Gambian army chief Ousman Badjie was seen celebrating Barrow's inauguration late on Thursday and had already declared he would not order his men to fight for Jammeh.
Soldiers were told by Barrow in his inauguration speech they would be considered rebel elements if they remained armed on the streets, and the few that remained on Thursday did not attempt to stop the spontaneous celebrations that broke out in Barrow's stronghold districts.
Vultures circled the deserted streets of Banjul on Friday morning, with the usual heavy military presence near absent.
"If they [foreign troops] come we will just stay in our homes and let them take him. If I had the chance I would apprehend him myself. He's messed up our lives," one Banjul resident told AFP under condition of anonymity.
On the ground, troops including "land, air and sea" forces crossed into The Gambia, a Senegalese army officer told AFP, indicating that Nigeria, Ghana, Togo and Mali were also involved.
A Senegalese army spokesperson confirmed his country's troops had crossed the border, after Nigerian jets earlier flew over The Gambia.
The uncertainty continued to push Gambians to flee the country and shelter with relatives in neighbouring states, while others living close to the capital returned to villages upcountry.
The United Nations refugee agency said around 45 000 had fled The Gambia so far, with more than 75% of those being sent out children, largely accompanied by women.
"They are staying with family members, host families or in hotels. Some families are hosting up to 40 to 50 people and will soon need support as they may quickly run out of resources," a United Nations High Commissioner for Refugees (UNHCR) report said.