Three-time Lebanese prime minister Saad Hariri was renamed to the post Thursday to create a reform-orientated cabinet that can lift the country out of its worst economic crisis in decades.

Hariri, 50, made his comeback to take on the difficult task almost a year after stepping down under pressure from an unprecedented protest movement demanding a complete overhaul of Lebanon's political system.

The country is under huge international pressure to form a crisis cabinet of independents to address a plummeting economy made worse by the coronavirus pandemic and the devastating blast at the Beirut port on August 4.

Immediately after President Michel Aoun named him, the returning premier vowed to form a cabinet of experts, in line with conditions set by French President Emmanuel Macron to help rescue the debt-ridden country from crisis.

Hariri said he would "form a cabinet of non politically aligned experts with the mission of economic, financial and administrative reforms contained in the French initiative roadmap".

To unlock desperately needed Western aid, Lebanese President Michel Aoun must designate a new prime minister capable of persuading the country's myriad of confessional factions to approve a government committed to reform
To unlock desperately needed Western aid, Lebanese President Michel Aoun must designate a new prime minister capable of persuading the country's myriad of confessional factions to approve a government committed to reform DALATI AND NOHRA / -

"I will work on forming a government quickly because time is running out," he said, calling it the country's "only and last chance".

He was set to start consulting the country's various parliamentary blocs from Friday, the parliament said.

Cabinet formation is often a drawn-out process in Lebanon, where a complex governing system seeks to maintain a precarious balance between its various political and religious communities.

Hariri himself took eight months to hammer out his last cabinet after 2018 parliamentary elections.

Lebanon's new prime minister designate Saad Hariri now has the task of persuading the country's myriad of factions to approve a new government committed to the reforms demanded by Western creditors
Lebanon's new prime minister designate Saad Hariri now has the task of persuading the country's myriad of factions to approve a new government committed to the reforms demanded by Western creditors AFP / ANWAR AMRO

His nomination on Thursday was backed by a majority of 65 lawmakers, while 53 abstained from naming anyone during consultations with the president.

The parliamentary bloc of the powerful Shiite Muslim movement Hezbollah did not give the president a name of a preferred candidate, but its main ally the Amal Movement supported Hariri's nomination.

The UN envoy to Lebanon Jan Kubis said the onus was once again on political parties to back change.

"It is the traditional political forces that have again put on themselves to choose the way forward, regardless (of) their numerous failures in the past and deep scepticism about the future," he wrote on Twitter.

There was no immediate reaction in the streets from the protest movement, which had however long said it did want the return of the political old guard it accuses of ineptitude and corruption.

A giant cut-out of a clenched fist, symbol of the anti-government protest movement, was set on fire during anti-Hariri protests on Wednesday but rebuilt the next day
A giant cut-out of a clenched fist, symbol of the anti-government protest movement, was set on fire during anti-Hariri protests on Wednesday but rebuilt the next day AFP / -

The European Union stressed the "need for the swift formation of a credible and accountable government".

US envoy David Schenker said any new government must implement reforms, and that Washington would carry on targeting Hezbollah and its allies with sanctions regardless.

"The United States will continue to pursue sanctions against Hezbollah and its Lebanese allies," he said, including over corruption.

Washington has long designated the group as "terrorist", but the movement is also a key player in Lebanese politics with seats in parliament.

Hariri's supporters fired celebratory gunshots in the northern city of Tripoli, which a medical source told AFP injured three including an elderly man and someone cleaning in front of their shop.

Hariri's return to politics comes after a catacylsmic explosion at Beirut's port killed more than 200 people and devastated swathes of the capital, in Lebanon's worst peacetime disaster.

Twenty-five people have been arrested over the August 4 blast, which occurred after a fire broke out in a warehouse storing hundreds of tonnes of ammonium nitrate.

But Human Rights Watch said Thursday the probe had failed to yield any credible results more than two months later, and called for an "independent, international investigation".

"Political interference coupled with long-standing failings of the judicial system have made a credible and impartial domestic investigation seemingly impossible," it said.

Outrage over the disaster blamed on official negligence led to the resignation of the government of prime minister Hassan Diab, who was replaced by a relatively unknown diplomat, Mustapha Adib.

But Adib faced resistance from some of the main parties and threw in the towel less than a month later, leaving Lebanon rudderless to face soaring poverty.

A small demonstration against Hariri took place in central Beirut late Wednesday.

Dozens of protesters shouted slogans against him and faced off with his supporters as security forces stepped in between both sides.

Local media said Hariri supporters burned a giant cut-out of a clenched fist bearing the word "revolution" in Arabic, but his party denied any involvement.

The emblem was rebuilt Thursday, an AFP photographer said.