Zimbabwe's long-time President Robert Mugabe has been holding direct talks with the army over his future.
Pictures emerged of the 93-year-old meeting the army chief and two envoys from South Africa at his official residence in Harare.
The army put Mugabe under house arrest on Wednesday after moving in to take control.
Opposition leader Morgan Tsvangirai says Mugabe must resign but sources suggest the president is resistant.
President Mugabe has been in control of Zimbabwe since it threw off white minority rule in 1980.
However, the power struggle over who might succeed him, between his wife Grace Mugabe and former Vice-President Emmerson Mnangagwa, has split the ruling Zanu-PF party in recent months.
Last week, Mugabe came down in favour of his wife, sacking Mnangagwa, a veteran of Zimbabwe's anti-colonial struggle.
That proved too much for military leaders, who seized control of the country on Wednesday.
It's very unclear what's going on in Harare now.
Photos in the Zimbabwe Herald showed Mugabe meeting army chief Gen Constantino Chiwenga and the two South African envoys from the Southern African Development Community (Sadc) at State House in Harare.
Alongside them was Father Fidelis Mukonori, a Roman Catholic priest known to Mugabe for years who has been brought in to mediate.
Sources close to the talks say Mugabe is refusing to stand down voluntarily before next year's planned elections.
"He is refusing to step down. I think he is trying to buy time," one source close to the army leadership told the AFP news agency.
Zanu-PF officials had earlier suggested Mugabe could remain nominally in power until the party congress in December, when Mnangagwa would be formally installed as party and national leader.
South Africa is hosting millions of Zimbabweans who fled after the country's economy crashed in 2008. It has a special interest in seeing stability restored.
South African Defence Minister Nosiviwe Maphisa-Nqakula and State Security Minister Bongani Bongo are the envoys meeting Mugabe on behalf of Sadc, which South Africa currently leads.
They will be pushing for a democratic solution. The body, which represents 16 countries, does not support coup-led governments as this would set a dangerous precedent in the largely peaceful region, says the BBC's Pumza Fihlani in Johannesburg.
The head of the African Union (AU), Guinean President Alpha Condé, was clear the AU would "in no case accept" a military seizure of power. He said he was "inviting the army to return to its barracks and return to constitutional order".
Tsvangirai, head of the Movement for Democratic Change-Tsvangirai (MDC-T) party and the main opposition leader in Zimbabwe, said on Thursday: "In the interests of the people, Robert Mugabe must resign... immediately."
Tsvangirai, who has been abroad receiving treatment for cancer, also called for a "negotiated all-inclusive transitional mechanism" that would lead to "comprehensive reforms for free and fair elections to be held".
This has been echoed by another Zimbabwean opposition leader, Tendai Biti, who told the BBC: "It is urgent that we go back to democracy... that we go back to legitimacy but we need a transitional period and I think, I hope, that dialogue can now be opened between the army and Zimbabweans."