France's President Emmanuel Macron (R) shakes hands with Lebanon's Prime Minister Najib Mikati as he welcomes him prior to their meeting at The Elysee Presidential Palace in Paris . AFP
But in the absence of key players, any political breakthrough appears remote around the conflict, which has so far claimed more than 1,500 lives and displaced 700,000 people.
Israel launched a ground offensive in southern Lebanon in late September after a year of exchanging fire with the Hezbollah group over the border.
Paris is also seeking an increase in humanitarian aid for a country to which it has historic ties and which has a large diaspora in France.
Foreign Minister Jean-Noel Barrot told broadcaster RTL on Wednesday that around 70 countries and 15 international organisations would attend, vowing that France "will not let Lebanon down".
"Everyone we invited said yes," he added, from a list which did not include Iran or Israel.
There has been uncertainty over what level of officials would attend the conference from each participating country, although Lebanon's Prime Minister Najib Mikati will be present.
French President Emmanuel Macron, who met with Mikati on Wednesday at the Elysee Palace, will open the conference.
"The president is doing his job by organising a summit to show that he's not abandoning the people of Lebanon, but I don't expect much from it," said Agnes Levallois of France's Iremmo Middle East research institute.
Nevertheless, the conference "is at least happening", said Hasni Abidi of the Geneva-based Cermam centre on the Arab world. He called the conference "the only diplomatic movement underway" since France and the United States pushed at last month's UN General Assembly for a temporary ceasefire in Lebanon.
'Not by military means alone'
German Foreign Minister Annalena Baerbock, during a surprise visit to Beirut, said that she would attend the Paris conference "to discuss with our international partners, Western as well as Arab, how a political solution to this situation can be found".
It was also "urgent to ensure, in coming days and weeks, that aid for the people of Lebanon arrives directly", she said.
"This conflict cannot be resolved by military means alone," Baerbock said.
EU foreign affairs chief Josep Borrell in a statement called the gathering "an important occasion to mobilise the urgent political and economic support to the Lebanese people and country's sovereignty".
On Thursday, "the objective is first of all to restate the need for a ceasefire, a diplomatic resolution and an end to hostilities," Barrot said.
France wants to "mobilise humanitarian aid from as many countries as possible," he added.
Macron's office said Wednesday that the conference would aim to fill the coffers of a $400-million UN appeal for aid to Lebanese displaced by the fighting.
In Lebanon, "the needs are so vast that even if the aid totalled hundreds of millions of dollars, you could cynically see it as a sort of palliative care," said Karim Bitar, an international relations expert at Beirut's Saint-Joseph University.
On the diplomatic front, France wants to re-apply UN Security Council resolution 1701, which sealed the end of the last Hezbollah-Israel war in 2006.
The document stipulates that the only armed forces on Lebanon's southern frontier with Israel should be UN peacekeepers and the Lebanese army.
Fully reinstating 1701 would "allow us to guarantee Lebanese sovereignty and unity on the one hand and on the other to give security guarantees to Israel", Barrot said.
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