The government of Malawi has confirmed the death of President Bingu wa Mutharika, two days after political and medical officials said he had died following a heart attack.
The delay in the official announcement, as well as the removal of Mutharika's body to South Africa on Thursday, had aroused suspicions about the succession process.
"We are sad to announce that the president of Malawi, Bingu wa Mutharika has died," Bright Msaka, secretary to the president and cabinet, said in a statement read on state radio on Saturday, who also declared 10 days of official mourning.
At a news conference held within hours of the official confirmation of Mutharika's death, Vice-President Joyce Banda said the constitution would be followed, but she held back from saying directly if she would be taking over as interim president.
"I don't think there's any way we can discuss who is caretaker and who is not," she said. "The constitution is prevailing right now."
AFP news agency said the head of the army, the chief of the national police, the attorney general, and several cabinet ministers and MPs were standing near her as she spoke.
"The paramount issue to be discussed at the cabinet meeting is on the funeral of the father of the nation," she said. "In the meantime, I call upon all Malawians to remain calm and to keep the peace during this time of bereavement."
According to the constitution, the vice-president takes over but there has been no official word on a successor.
Banda fell out with Mr Mutharika in 2010 and she was expelled from the ruling Democratic People's Party (DPP).
The president's brother, Peter Mutharika, the foreign minister, was lined up to be the DPP's presidential candidate in the 2014 elections.
The US, which has been an important aid donor for Malawi, expressed alarm at the official silence and said it did not want to see any delay in the swearing of Banda.
Constitutionally, Banda was expected to take over, but a smooth transition was not completely assured.
"Malawi's constitution lays out a clear path for succession and we expect it to be observed. We are concerned about the delay in the transfer of power," the US state department said in a statement.
Mutharika was rushed to hospital in the capital Lilongwe after collapsing on Thursday morning , and state media subsequently reported that he had been flown to South Africa for emergency treatment.
The Reuters news agency described chaotic scenes at the hospital as Mutharika's wife, Calista, and senior cabinet ministers left the building, amid concerns that the president's death could prompt political upheaval.
Police on Thursday were deployed across the country's capital, while 15 army officers took up positions around Banda's residence, witnesses said.
Mutharika, a former World Bank economist, came to power in 2004 and presided over a seven-year economic boom, underpinned by foreign aid and some favourable rains, that made Malawi one of the world's fastest-growing countries.
Ayesha Kajee, an independent political analyst who covers African affairs, said a small section of the populace would mourn Mutharika.
She told Al Jazeera many Malawians had "very high hopes" that he would turn Malawi's economy around "but since the first few years in power he has come to be regarded as being extremely corrupt".
Economic growth came to a halt last year, after a dispute with the United Kingdom led to diplomatic expulsions in both countries and the freezing of millions of dollars in aid to Malawi.
The aid suspension led to an acute shortage of dollars in the Malawian economy, hampering fuel, food and medicine imports.
Mutharika's diplomatic isolation and economic plight worsened in July 2011 when the US shelved a $350m programme to overhaul the country's dilapidated power grid, after police killed at least 19 people in a crackdown on an unprecedented wave of anti-government protests.