The speaker of parliament, Mohamed Ennaceur, said he would be the country's temporary president, in line with the constitution.
Tunisia’s 92-year-old president, Beji Caid Essebsi, who helped guide the North African country's transition to democracy after a 2011 revolution, has died, the presidency said on Thursday.
A leading figure in the country's fortunes since 2011, Essebsi was hospitalized late last month for a week after suffering what authorities described as a severe health crisis.
"On Thursday morning, the President of the Republic died at the military hospital in Tunis...The burial ceremony will be announced later," a presidency statement said.
The speaker of parliament, Mohamed Ennaceur, said he would be the country's temporary president, in line with the constitution. In a speech on national television, Ennaceur also called for unity following Essebsi's passing.
The prime minister declared seven days of national mourning. A source said Ennaceur's swearing-in would take place later in teh day.
Essebsi had been a prominent politician in Tunisia since the overthrow of autocrat Zine El-Abidine Ben Ali in 2011, which was followed by uprisings against authoritarian leaders across the Middle East, including in nearby Egypt.
Drafted in as a prime minister in 2011 after Ben Ali was toppled, Essebsi was elected president three years later, becoming the country's first directly elected head of state after its "Arab Spring" uprising.
Parliamentary elections are expected to be held on Oct. 6 with a presidential vote following on Nov. 17. They will be the third set of polls in which Tunisians have been able to vote freely following the 2011 revolution.
The presidency statement called on Tunisians to unite and safeguard their country's present and future.
"After the revolution, the president led the people to avoid confrontation and led the democratic transition and was keen to build and complete the constitutional institutions," it said.
Tunisia has been hailed as the only democratic success of the Arab Spring uprisings, with a new constitution, free elections and a coalition government with secular and moderate Islamists in a region otherwise struggling with upheaval.
But political progress has not been matched by economic advances. Unemployment stands at about 15 percent, up from 12 percent in 2010, due to weak growth and low investment.
Essebsi's death comes at a time of fresh attempts to replace dictatorships with democracy in the Middle East.
The armed forces of neighboring Algeria and Sudan ousted long-serving rulers of those countries after mass protests. But it remains unclear whether greater freedoms will result.