An international conference for Lebanon in Paris has raised $US1 billion ($1.5 billion) in pledges for humanitarian aid and military support to help the country where war between Hezbollah militants and Israel has displaced a million people.

More than 2500 have been killed and the violence has deepened an existing economic crisis.

The Paris conference gathered over 70 nations and international organisations.

In his closing speech to the summit, France’s foreign minister Jean-Noël Barrot said: “We have collectively raised $US800 million ($A1.2 billion) in humanitarian aid and $US200 million ($301 million) for the security forces, that’s about $US1 billion ($1.5 billion).”

French President Emmanuel Macron had called on participants to bring “massive aid” to support the country, as France promised $US100 million ($150 million).

“We’re up to the challenge,” Barrot said.

The United States pledged to provide about $US300 million ($451 million).

Germany promised a total of 96 million euros ($156 million) in humanitarian aid to both Lebanon and neighbouring Syria, also deeply affected by escalating violence in the Middle East.

Italy announced this week an additional 10 million euros ($US10.8 million ($16.2 million) in aid for Lebanon.

The United Nations had previously estimated the urgent humanitarian needs in Lebanon to be $US426 million ($A641 million).

However, experts warn that delivering aid could be challenging as Lebanon’s growing dependence on informal and cash economy increases lack of transparency and corruption risks.

The Paris conference also aimed at coordinating international support to strengthen Lebanon’s armed forces so they can deploy in the country’s south as part of a potential deal to end the war.

Such a deal could see Hezbollah withdraw its forces from the border.

This support to the Lebanese military includes “helping with health care, fuel, small equipment, but also supporting the plan to recruit at least 6000 additional soldiers and to enable the deployment of at least 8000 additional soldiers in the south,” Macron said.

The country, where Hezbollah effectively operates as a state within a state, has been without a president for two years while political factions fail to agree on a new one.

UN Secretary-General António Guterres, in a pre-recorded video, called on Lebanon’s leaders “to take decisive action to ensure the proper functioning of state institutions in order to meet the country’s urgent political and security challenges.”

Acting Lebanese Prime Minister Najib Mikati urged the international community to take action.

“The devastating impact of this war on our nation cannot be overstated, and it has left a trail of destruction and misery in its wake. The Israelis’ aggression has not only caused immense human suffering and loss of lives, but also inflicted severe damage to the country’s infrastructure, economy and social fabric,” Mikati said on Thursday in Paris.

The cash-strapped Lebanese government is ill-prepared to deal with the crisis or the increased demands on its health system.

Lebanon’s army has been hit hard by five years of economic crisis.

It has an aging arsenal and no air defences, leaving it in no position to defend against Israeli incursions or confront Hezbollah.

The Lebanese army has about 80,000 troops, around 5000 of them deployed in the south.

Hezbollah has more than 100,000 fighters, according to the militant group’s late leader, Hassan Nasrallah.

The militant group’s arsenal, built with support from Iran, is more advanced.

—AAP