No members of the last government of ousted president Maaouya Ould Taya, which had resigned on Sunday, were included according to the decree signed by junta leader Colonel Ely Ould Mohamed Vall on Wednesday.
The new line-up has 18 ministers plus Ould Boubacar, four junior ministers and a secretary-general to the government. The new cabinet includes technocrats who have not held ministerial portfolios before.
Vall's decree named Habib Ould Hemett as secretary general of the Military Council for Justice and Democracy (CMJD) chairman's office with the rank of minister.
Though he will attend cabinet meetings, he is not officially part of the government.
Vall was expected to act as defence minister.
The new foreign minister is Ahmed Ould Sid'Ahmed, who in the same post in 1999 signed an accord in Washington sealing diplomatic relations with Israel. Ould Sid'Ahmed also was Mauritania's ambassador to Syria.
His appointment seemed aimed at reassuring international critics, especially the United States, of the junta's good intentions following the bloodless coup that toppled Washington's ally Ould Taya on 3 August after more than two decades in power.
Mahfouz Ould Bitah, former bar association leader and prominent human rights activist, was named justice minister.
African Union meeting
African Union officials on Wednesday emerged reassured from talks with the new rulers but said the country would remain suspended from the pan-African body until democracy returns.
Ould Boubacar was named prime
minister three days ago
Nigerian Foreign Minister Oluyemi Adeniji, head of an AU mission that arrived in Nouakchott on Tuesday, told reporters on Wednesday, "We are reassured because there is a consensus on the need for change.
"We think it will be much easier to steer the process for returning the country to democracy."
Adeniji said that Vall "promised us that he will launch this programme and complete it as soon as possible, and we hope that this will be sooner than the two years which were mentioned".
The Nigerian minister, whose country holds the rotating AU presidency, praised the peaceful atmosphere in Mauritania and the unanimous approval of the 3 August coup.
But he said that while it was not his mission's function to give an opinion on the northwest African country's suspension from the AU, it was usual to maintain such sanctions until the return of democracy after transparent elections.
Envoys of the Arab Maghreb Union (UMA) headed by Libyan Foreign Minister Abderrahman Shalgham also met Vall in Nouakchott on Tuesday.
"We think it will be much easier to steer the process for returning the country to democracy"
Nigerian Foreign Minister Oluyemi Adeniji
In the first comment on the coup by the regional organisation that groups Mauritania with Algeria, Libya, Morocco and Tunisia - Shalgham said that it "could not oppose the voluntary choice of the Mauritanian people".
He declined to say whether the UMA recognised the new government pending a report to the other member states.
President Abdoulaye Wade of neighbouring Senegal spoke to Vall on Monday by telephone, saying he was prepared to help in a peaceful transition to a civilian government and to dispatch his foreign minister Tidiane Gadio to Nouakchott, according to the Mauritanian news agency.
US reversed position
The AU official's remarks seemed to dash any hopes that Ould Taya might have had of securing the pan-African body's aid for a return to power, after a reversal of Washington's earlier demand that the ousted president, a strong regional ally, should be restored.
US deputy State Department spokesman Adam Ereli said on Monday, "We're not insisting on a given outcome other than it be a restoration of constitutional rule, constitutional procedures and constitutional practices, consistent with international standards."
Ereli said the United States would work with the AU and others "to see that government in Mauritania is consistent with international standards and respects the will of the people and is responsive to the people".
Ould Taya in Gambia
Ould Taya was settling down in his new home in Gambia, where he arrived late Tuesday from Niger, according to an airport official in Banjul.
Ousted president Ould Taya left
Niger for Gambia
He was believed to be heading to the Senegambia tourist resort outside the capital.
He had sought refuge in Niger in the wake of the coup that ended his two decades of iron-fisted rule while he was in Saudi Arabia for the funeral of King Fahd.
His departure from Niger came a day after he read a televised statement ordering the security forces, "as the president of the republic ... to put an end to this criminal operation in order to restore the situation to normal."
His order was totally ignored by the military and condemned by Mauritanian politicians, who called it a dangerous incitement to civil war.