Five candidates are vying for the AU's top job. Kenya's foreign minister Amina Mohamed, Chad's former Prime Minister Moussa Faki Mahamat and Senegal's veteran diplomat Abdoulaye Bathily are the frontrunners in the race. The two other candidates are Agapito Mba Mokuy from Equatorial Guinea and Botswana's Pelonomi Venson-Moitoi.

Kenya has been vigorously lobbying for its candidate, Mohamed. The government formed a committee last year that toured 51 African states to garner support for her. Fifty-five-year-old Mohamed served as the United Nations assistant secretary-general and deputy executive director of the United Nations Environment Program in Nairobi.

The West African bloc put forward 69-year-old Senegalese Abdoulaye Bathily as its candidate. Bathily is a senior minister in the Office of the President of Senegal and a special representative of the UN secretary-general for Central Africa. Bathily has been vocal about Africa's interests in the UN.

Botswana's 65-year-old Pelonomi Venson-Moitoi is backed by her southern bloc neighbor, South Africa. Moitoi is the current minister of foreign affairs of her country, a position she assumed in 2014. 

Each candidate needs at least 34 votes to secure the seat as the next AU Commission chair and requires at least 11 votes to remain in the race at the first round of voting. 

The politics of AU voting

Analysts say the alignment of countries across the continent shows that countries will vote along their regional economic blocs or as influenced by their local politicians. Dr. Patrick Muluki from Nairobi University's Diplomacy and International Studies Institute tipped Amina Mohammed as one of the top contenders going by the Union voting blocs. 

"The AU elections are mainly determined by regional blocs. We have five blocs. One of the advantages Amina has is that she has been endorsed by the East African Community bloc. She goes with an advantage of about 14 votes as opposed to other candidates, who have not been endorsed by their region," Muluki said.

The five blocs of the AU are the East African Community, Southern African Development Community, the Economic Community of West African States, the Economic Community of Central African States and the Arab Maghreb Union.

Muluki said that the Francophone-Anglophone issue is also at play with the West African bloc's votes divided between Chad and Senegal. "Senegal has a strong top candidate, but so does Chad. Those two are Francophone countries, and that is something they have to square off. But ECOWAS has not endorsed Senegal's candidate," he added.

Traditionally, the chairmanship rotates between English-speaking and Francophone countries. The previous chairperson, South Africa's Nkosazana Dlamini-Zuma, was from an Anglophone country.

The return of the prodigal member

Morocco's bid to rejoin the Africa Union (AU) after 33 years is also one of the major highlights in the two-day summit in Addis Ababa. The North African nation quit the AU in 1984 in protest of a decision by the body's predecessor, the Organization of African Unity, to accept Western Sahara as a member. Since Morocco applied to rejoin the union in July 2015, its monarch, King Mohammed VI, has been crisscrossing the continent lobbying for support.

"The AU has become more and more relevant, so Morocco realizes it cannot drive an [economic] agenda on the continent without being in the AU," said Liesl Louw-Vaudran, a consultant with the Institute for Security Studies (ISS) in Addis Ababa.

The membership of Morocco could also be a financial boon for the AU. Currently, foreign donors account for some 70 percent of its budget, according to the ISS. But Louw-Vaudran believes Morocco's return is still "not a done deal" since heavyweights such as Algeria and South Africa are lobbying hard against the move. 

Algeria and South Africa support the fight of Western Sahara's Polisario Independence Movement for self-governance. Morocco maintains that the former Spanish colony, which it annexed in 1975, is an integral part of its kingdom.

"The question now is whether Morocco's reintegration means Western Sahara will now be excluded," said Senegal-based political analyst Gilles Yabi. "This is where there are very clear divisions in the AU."

Political bickering

The summit is also expected to discuss several crises on the continent, especially the conflict in South Sudan, where ethnic violence has continued. Tens of thousands have died and more than three million have been displaced since the violence broke out in 2013.

A 4,000-strong regional protection force mooted at the last AU summit has been mired in delays and disputes as South Sudan's government insists the force is no longer needed. "There hasn't been a sense of urgency to save lives and get this force up and running," said Louw-Vaudran. "I think it is just South Sudan fatigue; they are out of any ideas of how to solve this [crisis]."

Another issue dividing African leaders is a growing discontentment over the International Criminal Court. Burundi, South Africa and The Gambia decided late last year to pull out of the court, claiming it unfairly targets African nations. Others, such as Kenya, threatened to follow suit, but Botswana and Senegal argued in the court's favor.

Other key subjects will be the turmoil in Libya, radical Islamism in Mali, Somalia and Nigeria and the ongoing political tensions in the Democratic Republic of Congo.

During the summit, Rwanda's president Paul Kagame is expected to submit his first report on suggested reforms for the African Union, which has long been weighed down by bureaucracy.

The summit comes after several shake-ups on the international stage: the election of US President Donald Trump and a new head of the UN, Antonio Guterres, who will also be attending the summit.