Haitian Prime Minister Ariel Henry resigned on Thursday and a transitional council took power with the aim of returning stability to a country where gang violence has caused chaos and misery.

Henry's former finance minister, Michel Patrick Boisvert, will be interim prime minister.

"Today is an important day in the life of our dear republic, this day in effect opens a view to a solution... to the multidimensional crises the country faces," Boisvert said after the formal swearing-in of the nine-person transitional council on Thursday morning.

Top police and military officials and members of the transitional council stood behind Boisvert during the ceremony, hosted at the prime minister's office known as Villa d'Accueil, which was surrounded by military and a security detail.

Henry announced last month he would resign once the council was in place.

He left Haiti in February to seek international help for police in their battles with armed and powerful gangs. But he was left stranded outside the country as the gangs threatened to completely take over the capital. Struggling to return, Henry announced his intended resignation. Boisvert had served as acting prime minister in Henry's absence.

The transitional government's mandate runs until February 2026, by when there are slated to be elections, and cannot be renewed.

But the path to getting to elections was long, and there were already tensions within the council as different factions jostled for power, said Diego Da Rin, an analyst with the International Crisis Group.

"Despite the installation, there is still a long and rocky road ahead for the council to be able to forge a government," Da Rin said.

The naming of the council is also seen as key step towards the deployment of a multinational security mission. Kenya had offered to head that mission but then put it on pause as the security situation deteriorated, saying it would re-evaluate once a new government was in place.

UN Secretary-General Antonio Guterres called for the multinational force to happen quickly to help tackle the "dire" situation, his spokesperson said on Thursday. (Reuters)