Tunisia's president-elect Kais Saied has won a clear mandate to fight corruption and promote social justice, even though his role focuses on security and diplomacy.

Here is an overview of key policy challenges facing the conservative newcomer:

Change in foreign policy?

A constitutional law professor by trade, Saied has no real experience in foreign policy.

So far, he has proposed "principles more than a concrete road map", according to former diplomat Taoufik Ouanes.

"While sticking to fundamentals, he will make adjustments to Tunisian diplomacy," he said.

Tunis, which currently chairs the Arab League, "could renew diplomatic ties with Syria (ceased in 2012) and play a role in the return" of the war-torn country to the bloc.

Saied has made strong statements against Israel, considering any ties with the Jewish state to be "high treason" -- an Arab nationalist position that earned him praise among supporters.

Tunis currently has no diplomatic relations with Israel.

Ouanes added that Saied could also "call for a revision of the rules concerning foreign investment in the country".

Tunisia is currently negotiating a trade deal with the European Union. Ouanes said Saied could "ask that the negotiations take Tunisia's interests more into account".

France, the former colonial power in Tunisia, called for an "expansion" of ties during a phone call between President Emmanuel Macron and Saied.

What are the security challenges?

While the security situation has significantly improved since a series of attacks in 2015, Tunisia has maintained a state of emergency for four years, with assaults against security forces persisting.

On June 27, a suicide attack killed two people in the heart of the capital Tunis, reviving the spectre of violence.

Saied won Sunday's presidential runoff by a landslide
Saied won Sunday's presidential runoff by a landslide AFP / Fethi Belaid

During a televised debate ahead of Sunday's runoff vote, Saied said a key to fighting terrorism was education, arguing that improving primary education would "immunise" youth against extremism.

He also said he considers access to healthcare and water a part of national security, hinting that he would like to be involved directly in improving these.

Another significant task is reforming the police, which was a cog in the dictatorship toppled by the 2011 revolt and which continues to be accused of human rights abuses.

Room to manoeuvre on the economy?

Under the constitution, it is the government's role to take the lead on the economy.

But given his strong voter backing, Saied could intervene in negotiations to form a government, or even in devising its economic and social policies.

Saied could also launch presidential initiatives -- proposing bills to parliament or funds for youth employment, for example.

Many Tunisians hope that their president-elect, a man who owes nothing to the country's economic elites, will bring more social justice.

Is radical decentralisation possible?

Saied has advocated direct democracy via local councils to better reflect "what the people want" in place of the party system in force in parliament.

But the assembly would likely look unfavourably on voting for its own dissolution.

To an extent the decentralisation of power, a key demand of the 2011 revolution, is already under way.

But the process has so far been slow, given the lack of political will.

A code for local authorities was adopted before the 2018 municipal elections, but less than a sixth of its decrees have been approved.

"Elected officials and ministries were opposed to power-sharing," said Nessryne Jelalia, director of Tunisian NGO Al-Bawsala.

"We now have a president and parties in parliament who have made it their campaign centrepiece," she said.