Assimi Goita - the Malian colonel who has overthrown two presidents in the past nine months - was sworn in as interim president on Monday (June 7).
The 38-year-old special forces commander had already been declared president by the constitutional court last month.
He was formally sworn in during a ceremony in the capital, where he vowed to oversee a transition toward democratic elections:
"This new situation offers us the opportunity to put the process of transition back in the direction desired by the people. The challenges are immense, the legitimate expectations of the people are as big."
Goita is under pressure from regional and international powers to ensure elections go ahead next February as scheduled.
As many worry the political upheaval could strengthen Islamist insurgents based in the country's desert north.
Goita was one of several colonels who overthrew President Ibrahim Boubacar Keita last August.
He then arrested serving president Bah Ndaw and the prime minister last month. Both later resigned while in custody.
Last week, West African regional bloc ECOWAS and the African Union suspended Mali from their organizations, but declined to impose further sanctions.
The World Bank said it had temporarily paused payments to the country on Friday (June 4) and France said it would temporarily suspend joint military operations with Malian troops.