The long-awaited move comes as gangs continue to terrorise the capital of Port-au-Prince, opening fire in once peaceful neighbourhoods and using heavy machinery to demolish several police stations and prisons.

Council member Louis Gérald Gilles told The Associated Press that six out of seven council members with voting power chose Conille earlier Tuesday. He said one member, Laurent St. Cyr, was not in Haiti and therefore did not vote.

Conille is UNICEF's regional director for Latin America and the Caribbean and previously served as Haiti's prime minister from October 2011 to May 2012 under then President Michel Martelly. He replaces Michel Patrick Boisvert, who was named interim prime minister after Ariel Henry resigned via letter in late April.

Henry was on an official trip to Kenya when a coalition of powerful gangs launched coordinated attacks on February 29, seizing control of police stations, shooting at Haiti's main international airport and storming the country's two biggest prisons, releasing more than 4,000 inmates.

Henry was locked out of the country by the attacks, with the airport in the Port-au-Prince capital remaining shuttered for nearly three months.

Gang violence is still surging in parts of Haiti's capital and beyond as Conille takes over the helm of the troubled Caribbean country awaiting the UN-backed deployment of a police force from Kenya and other countries.

Conille studied political and health administration and helped develop health care in impoverished communities in Haiti. He worked for several years at the United Nations before Martelly designated him as prime minister in 2011. Conille resigned less than a year later following clashes with the president and his Cabinet over an investigation into government officials who have dual nationality, which is not allowed by Haiti's constitution.

Conille has an arduous task ahead of him, having to quell rampant gang violence while helping lift Haiti out of deep poverty, with inflation reaching a record 29 per cent, according to the latest data available.

In recent years, gangs that control at least 80 per cent of Port-au-Prince have forced more than 360,000 people from their homes, and they continue to control key routes from the capital to Haiti's northern and southern regions, often paralyzing the transportation of critical goods.

The selection of Conille as prime minister comes just weeks after former Haitian sports minister Fritz Bélizaire was chosen for the post in late April by a four-member coalition within the nine-member transitional council in a surprise announcement that angered many. Critics said proper procedure was not followed as dictated by the framework that established the council, so a new process was started to choose a prime minister, with dozens of names submitted for the post.

The drawn-out process has been criticized by many, including the Montana Accord, a Haitian civil society group that has a representative on the council.

In a statement Tuesday, the group accused the council of not taking any “consequential measures” since being installed as “the suffering of the people is getting worse, while the gangs are taking control of more territory and committing more crimes”.

It also accused the council of not being transparent while choosing a new prime minister, saying it did not publicly share the criteria used or the names submitted, among other things.

Liné Balthazar, president of the Tet Kale party, called on the council to be transparent in an interview on Monday with Magik9, a local radio station, and said the selection of a prime minister appeared improvised.

In addition to selecting a new prime minister, the nine-member council, of which seven have voting powers, also has to appoint a provisional electoral commission, a requirement before elections can take place. The council's non-renewable mandate expires February 7, 2026, at which date a new president is scheduled to be sworn in.

In addition to picking a new prime minister, the council also is responsible for selecting a new Cabinet and holding general elections by the end of next year.

The council members are Emmanuel Vertilaire for Petit Desalin, a party led by former senator and presidential candidate Jean-Charles Mo?se; Smith Augustin for EDE/RED, a party led by former Prime Minister Claude Joseph; Fritz Alphonse Jean of the Montana Accord; Leslie Voltaire for Fanmi Lavalas, the party of former President Jean-Bertrand Aristide; Louis Gérald Gilles for the December 21 coalition that backs former Prime Minister Ariel Henry; Edgard Leblanc Fils for the Jan. 30 Collective, which represents parties including that of former President Michel Martelly; and Laurent Saint-Cyr for the private sector.