Malian interim President Diouncounda Traore has appointed a new PM, less than 24 hours after his predecessor was forced to resign by the military.
Django Sissoko, an official in the presidency, has been named to succeed Cheick Modibo Diarra, who has been under arrest since his resignation.
The appointment was announced on state television.
The role of the military in the forced resignation of Mr Diarra has been condemned by the UN and many countries.
But Capt Amadou Sanogo, who led a coup in March, said Mr Diarra had not been forced to quit and the military had only facilitated his resignation.
Mali has been in disarray for much of the year. Islamist and Tuareg separatists seized control of the north of the country and discontented soldiers staged a coup after the civilian administration was unable to regain control of all of the country.
Mr Traore had promised to appoint a civilian successor to Mr Diarra within 24 hours, but it is uncertain whether the naming of Mr Sissoko will be enough to satisfy international calls for a return to democracy.
The United Nations had threatened to impose sanctions over Monday’s arrest and the Security Council said it was ready to take “appropriate measures” against those who undermined Mali’s stability.
“The members of the Security Council express their readiness to consider appropriate measures, including targeted sanctions, against those who prevent the restoration of the constitutional order and take actions that undermine stability in Mali,” the council said in a statement.
UN Secretary General Ban Ki-moon said he was “troubled” by the latest developments, which underscored the importance of national and international efforts to address the political crisis in Mali.
The United States called the return of the military into Malian politics as a “setback” to democracy and the regional body, Ecowas, condemned the action.
Mr Diarra was made prime minister of an interim government in April after the military officially handed power back to civilians.
But tensions have been mounting in recent weeks between the soldiers who led the coup and the civilian prime minister they were forced to appoint.
The 60-year-old astrophysicist has backed plans to send a West African intervention force into the northern half of Mali which was seized after the coup by Islamists and Tuareg separatists.
However, many within Mali’s military are opposed to foreign intervention, saying they need only financial and logistical support.
Earlier, the West African regional group Ecowas agreed to send 3.300 troops to reclaim rebel-held territory. The deployment has been backed by UN Secretary General Ban Ki-moon.
And on Monday, the European Union backed plans for a 250-member training mission for about four battalions of the Malian army to fight the militants.