Colonel Mamady Doumbouya, who led last month's coup in Guinea, was sworn in as interim president on Friday promising to respect all the West African state's international commitments.
Doumbouya, who led the overthrow of president Alpha Conde on September 5, was sworn in by Supreme Court head Mamadou Sylla for a transition period of unspecified length.
The new interim president spoke of his "commitment" that neither he nor any member of the junta would stand in any future elections that the military have promised to organise after a transition period.
His administration's mission is to "refound the state" he said, by drafting a new constitution, fighting corruption, reforming the electoral system and then organising "free, credible and transparent" elections.
He once again said nothing at the time of his swearing in about how long he will remain the interim leader.
The new president also promised to "respect all the national and international commitments to which the country has subscribed."
Wearing a beige dress uniform, red beret and dark glasses, the new national leader also vowed to "loyally preserve national sovereignty" and to "consolidate democratic achievements, guarantee the independence of the fatherland and the integrity of the national territory".
The ceremony was held at the Mohammed-V palace in Conakry on the eve of a public holiday celebrating the 1958 declaration of independence from France.
Doumbouya will serve as transitional president until the country returns to civilian rule, according to a blueprint unveiled by the junta on Monday that does not mention a timeline.
The September 5 coup, the latest bout of turbulence in one of Africa's most volatile countries, saw the overthrow of 83-year-old president Conde.
Conde became Guinea's first democratically elected president in 2010 and was re-elected in 2015.
But last year he pushed through a controversial new constitution that allowed him to run for a third term in October 2020.
The move sparked mass demonstrations in which dozens of protesters were killed. Conde won re-election but the political opposition maintained the poll was a sham.
The "charter" unveiled on Monday vows that a new constitution will be drafted and "free, democratic and transparent" elections held, but does not spell out how long the transition will last.
The document says the transitional president will be "head of state and supreme chief of the armed forces... (and) determines the policies of the Nation," with the power to name and fire an interim prime minister.
However, the president will be barred from being a candidate at the elections that will take place after the transition, it says.
The turbulence in the former French colony has sparked deep concern among Guinea's neighbours.
The coup is the second to take place in the region, after Mali, in less than 13 months.
The region's bloc, the Economic Community of West African States (ECOWAS), is demanding that elections be held within six months, as well as Conde's release.