The US and France have called for a 21-day temporary ceasefire between Israel and Hezbollah to make way for broader negotiations, as the UN secretary general, António Guterres, told a UN security council meeting that “hell is breaking loose” in Lebanon.

Israel’s top general has said the country is preparing for a possible ground operation into Lebanon after an intense three-day bombing campaign that has killed more than 600 people, further fuelling fears of a regional conflict.

The joint statement issued by US president Joe Biden and French counterpart Emmanuel Macron said: “It is time for a settlement on the Israel-Lebanon border that ensures safety and security to enable civilians to return to their homes. The exchange of fire since October 7th, and in particular over the past two weeks, threatens a much broader conflict, and harm to civilians.”

The two leaders, who met on the sidelines of the UN general assembly in New York, said they had worked on a temporary ceasefire “to give diplomacy a chance to succeed and avoid further escalations across the border”.

They urged Israel and Lebanon to back the move, which was also endorsed by the UK, Australia, Canada, the European Union, Germany, Italy, Japan, Saudi Arabia, the United Arab Emirates and Qatar.

A senior US administration official said on Wednesday night that both Israel and Lebanon, which was understood to be representing Hezbollah in the negotiations, were expected to respond to the call “in the coming hours”.

Officials in a background briefing also emphasised that the ceasefire proposal does not apply to the conflict between Israel and Hamas in Gaza.

The US said that the 21-day period was chosen in order to provide space in order to negotiate a more comprehensive agreement between the two sides to allow residents to return to their homes along the Israel-Lebanon border without fear of further violence or an “October 7th-like attack in the future”.

The statement from the 12-member bloc said: “The situation between Lebanon and Israel since October 8th, 2023 is intolerable and presents an unacceptable risk of a broader regional escalation. This is in nobody’s interest, neither of the people of Israel nor of the people of Lebanon.”

The announcement came at the conclusion of a heated UN security council meeting, which saw Lebanon’s prime minister accuse Israel of violating his country’s sovereignty. Najib Mikati said Lebanese hospitals were overwhelmed and unable to accept any more victims.

Israel’s UN envoy told the security council said that his country did not seek a full-scale war and that Iran was the “driving force” behind the instability sweeping the Middle East.

For his part, Iranian foreign minister Abbas Araqchi said the US and UK’s “unwavering support for Israel has given them carte blanche for all sorts of sinister behaviour”.

There have been tensions between the US and its European allies about whether to call for an immediate ceasefire at the security council. The UK foreign secretary David Lammy backed an immediate ceasefire, saying it was time to pull back from the brink, adding “a full blown war is not in the interests of Israeli or Lebanese people”.

He said nothing justified Hezbollah’s attacks and urged Iran to use its influence to persuade Hezbollah to agree to a ceasefire.

But US diplomats indicated an unconditional ceasefire call in the form of a joint security council statement could be seen as accepting a moral equivalence between the behaviour of Israel and Hezbollah, a group that is labelled a terrorist group by the US.

The proposal for a temporary three-week cessation of hostilities might provide a platform to reopen stalled talks on the discussions over a ceasefire between Hamas and Israel in Gaza. Hezbollah has said it will stop its strikes if Hamas agrees to a Gaza ceasefire, but there is no sign currently of either the Hamas leadership or the Israeli prime minister Benjamin Netanyahu coming to an agreement.

Netanyahu was due to arrive in New York on Thursday, and is expected to set out whether he supports a 21-day break in hostilities.

The US deputy envoy Robert Wood said “diplomacy will only become more difficult” if the conflict escalates further, adding he was gravely concerned by reports that hundreds of Lebanese civilians had died in recent days.

But he insisted the origin of the conflict was the hundreds of thousands of Lebanese civilians, and 65,000 Israeli civilians, who have been displaced due to Hezbollah’s decision on 8 October to break the peace that has largely endured.

He said that no one wanted to see a repeat of the war in 2006, adding “the war must end with a comprehensive undertaking that has real implementation mechanisms”.

No details of the implementation mechanisms were set out by the US envoy, but it is not likely to be backed by Hezbollah if it infringes on its sovereignty.