Vatican Secretary of State Pietro Parolin on Wednesday urged warring parties in the Middle East to accept "peace proposals", saying the region including Lebanon "doesn't need war".

"The Middle East is going through a critical moment," Parolin told a press conference in Beirut during a days-long visit to Lebanon.

The Holy See "asks for peace proposals to be welcomed, so that fighting stops on each side, so hostages in Gaza are released, so that the necessary aid arrives unhindered to the Palestinian population", he said.

The outgoing United Nations humanitarian chief warned Wednesday that a spread of the Israel-Hamas war to Lebanon would be "potentially apocalyptic", as fighting raged in the southern Gaza Strip.

Martin Griffiths described Lebanon as "the flashpoint beyond all flashpoints", especially its southern border with Israel which has seen daily cross-border violence since the October 7 Hamas attack on Israel.

"It's beyond planning. It's potentially apocalyptic," warned Griffiths whose term as UN humanitarian coordinator ends this week.

Iranians vote on Friday to elect a new president from six candidates, including a lone reformist who hopes he can challenge the dominance of conservatives in the Islamic republic.

A presidential election had not been due until 2025, but was brought forward after ultraconservative Ebrahim Raisi died in a helicopter crash last month.

The snap poll comes at a challenging time as Iran grapples with the economic impact of international sanctions amid heightened regional tensions over the Gaza war between Israel and Tehran's ally Hamas.

The United States is pressing Israel to avoid a major war against Lebanon's Hezbollah, with top American officials urging a diplomatic solution in order to prevent another Middle East crisis.

Israeli forces and Iran-backed Hezbollah are exchanging fire on a near-daily basis, and the Israeli army said last week that plans for an offensive in Lebanon were "approved and validated."

US Defense Secretary Lloyd Austin met his Israeli counterpart Yoav Gallant at the Pentagon on Tuesday, warning that a conflict between Israel and Hezbollah could spark a regional war and urging a diplomatic solution.

More than eight months of war in Gaza has heightened tensions across the region, with Israeli forces and Lebanon's Iran-backed Hezbollah exchanging fire on a near-daily basis.

Iranian supreme leader Ayatollah Ali Khamenei called for "high participation" in Friday's presidential election to replace Ebrahim Raisi, who died last month in a helicopter crash.

"We emphasise the importance of high participation (in the election) because it is the pride of the Islamic republic," Khamenei declared in a televised speech three days ahead of the vote.

"In every election where the turnout was low, the enemies of the Islamic republic have denounced us," he added.

Israel's top court ruled unanimously on Tuesday that the state must draft ultra-Orthodox Jewish men into military service, potentially destabilising Prime Minister Benjamin Netanyahu's ruling coalition.

The High Court of Justice's decision on the politically charged issue comes as calls grow for ultra-Orthodox men, historically exempt from mandatory service, to enlist as Israel wages war on Hamas in Gaza and prepares for potential fighting in Lebanon.

Palestinian militant group Hamas said an Israeli air strike early Tuesday killed 10 family members of its Qatar-based chief Ismail Haniyeh, who vowed to continue the "resistance" movement against Israel.

Israel's military, which is on a campaign to destroy Hamas over the October 7 attack, told AFP that it "was aware of the reports but we cannot confirm" them.

The strike hit the Haniyeh family home in Al-Shati refugee camp in the northern Gaza Strip, Hamas and Gaza's civil defence agency said.

The United States warned Israel Tuesday that a conflict with Hezbollah could spark a regional war, as UN agencies said 10 children a day are losing one or both legs and half a million Palestinians suffer "catastrophic" hunger in Gaza.

US Defence Secretary Lloyd Austin met his Israeli counterpart Yoav Gallant at the Pentagon, saying diplomacy is the best option as fears of a major war against Iran-backed militant group Hezbollah in Lebanon have grown after months of cross-border fire.

A collaborative investigation by international media outlets on Tuesday shed light on the circumstances behind more than 100 Palestinian journalists and media workers being killed in the Gaza war, some while wearing a press vest.

A consortium led by investigative outlet Forbidden Stories and involving around 50 journalists from 13 organisations including AFP, The Guardian and the Arab Reporters for Investigative Journalism group (ARIJ) took part in the four-month probe.