Mauritanians are voting for the first time since the country gained independence from France in 1960.
The 62-year-old is standing down after serving the maximum two five-year elected terms.
However the status quo is likely to prevail when a new leader is elected.
Abdel Aziz has expressed his support for Mohamed Ould Ghazouani, who is a former general and defense minister.
Rubio tells Munich security forum US, Europe belong together
US Secretary of State Marco Rubio gave a message of unity to Europeans on Saturday, saying Washington does not intend to abandon the transatlantic alliance, but that Europe's leaders had made a number of policy mistakes and need to change course.
Canadians 'will always be with you' says PM at Tumbler Ridge vigil
Canadian Prime Minister Mark Carney told grieving residents of Tumbler Ridge, British Columbia, on Friday that Canadians "will always be with you" at a vigil to mourn victims of one of the country's worst mass shootings.
UN Chief urges unity as Ramadan approaches
UN Secretary-General António Guterres issued a message to the international community on Friday, as the holy month of Ramadan approaches, emphasising that the sacred period is a time for reflection and prayer, embodying a vision of hope and peace.
BNP sweeps Bangladesh election, Tarique Rahman set to become PM
Bangladesh Nationalist Party (BNP) won a landslide parliamentary election on Friday, returning to power after nearly two decades and positioning party leader Tarique Rahman to become prime minister.
France detains nine in probe over alleged $11.8 mln Louvre ticket fraud
French police arrested nine people in an investigation into a Louvre ticket fraud that may have cost the world's most visited museum 10 million euros ($11.86 million) in revenues, the Paris prosecutor's office said on Friday.
