Optimism that a three-week ceasefire could be reached between Hezbollah and Israel appeared to recede as Benjamin Netanyahu issued a pair of contradictory statements on the proposal within hours of each other.

In the latest statement from Netanyahu’s office, issued overnight on Friday, the Israeli prime minister chided reporting on the issue as he confirmed Israel had been consulted regarding a US-led ceasefire proposal.

“Israel shares the aims of the US-led initiative of enabling people along our northern border to return safely and securely to their homes. Israel appreciates the US efforts in this regard because the US role is indispensable in advancing stability and security in the region,” the statement read.

A previous release earlier on Thursday, however, had said that reporting “about a ceasefire is incorrect. This is an American-French proposal that the prime minister has not even responded to.”

Netanyahu’s twin statements appeared to replicate his response to previous US-led diplomatic initiatives over a Gaza ceasefire, where Israel has suggested it is more open to talks in private before reversing in the face of opposition from his coalition members.

Not for the first time US officials appear to have been wrongfooted by Netanyahu, saying initially they had believed his government was “onboard” with the plan for a 21-day ceasefire when it was announced by the US, France and other allies, saying the proposal had been “coordinated” with Israel.

“We had every reason to believe that in the drafting of it and in the delivery of it, that the Israelis were fully informed and fully aware of every word in it,” John Kirby, the White House national security spokesperson, told reporters on Thursday, adding that the US “wouldn’t have done it if we didn’t believe that it would be received with the seriousness with which it was composed”.

The late-night statement came after Abdallah Bou Habib, Lebanon’s foreign minister, urged all parties to implement the proposal, saying the escalating violence threatened his country’s “very existence”.

Speaking at the UN general assembly in New York, Bou Habib said the US-French ceasefire proposal was an “opportunity to generate momentum, to take steps towards ending this crisis”.

Earlier, the office of Netanyahu – who is addressing the UN general assembly on Friday – said the IDF would “continue fighting with full force” to achieve its war goals. Those war goals include the safe return home of more than 60,000 Israelis forced to abandon their homes in northern Israel by Hezbollah bombing, which began on 8 October last year, the day after the start of the Gaza war.

On Thursday, Lebanon’s health ministry said nearly 700 people had been killed this week, as Israel dramatically escalated strikes it says are targeting Hezbollah’s military capacities. The IDF said a strike on a southern suburb of Beirut killed the head of Hezbollah’s drone force, Mohammad Surur. Israel has carried out several strikes in Beirut this week, targeting senior Hezbollah commanders.

After the Beirut explosion, dozens of rockets were fired toward the northern Israeli city of Safed, with one hitting a street in a nearby town. In total, 175 projectiles were fired from Lebanon on Thursday, the military said. Most were intercepted or fell in open areas, some sparking wildfires.

The IDF said on Friday it had intercepted a missile fired from Yemen that set off air raid sirens across Israel’s populous central area, including Tel Aviv. Another missile from Yemen landed in central Israel about two weeks ago. The strikes came after Israel’s military chief said on Wednesday the country was preparing for a possible ground operation in Lebanon.

On Thursday, the Israeli army spokesperson Avichay Adraee reiterated that the military was preparing for a ground operation while awaiting a decision on whether to go ahead, and that the air force had reduced Hezbollah’s weapons stockpile and was working to prevent the transfer of further arms from Iran.

Hezbollah has yet to respond to the call for a truce, although it and its backer Iran have previously said it would halt its strikes only if there is a ceasefire in Gaza.

Emmanuel Macron – who was a co-backer with Joe Biden of the 21-day ceasefire proposal – said Netanyahu would have to take responsibility for a regional escalation if he did not agree to the truce. “The proposal that was made is a solid proposal,” the French president said, adding that the plan supported by the US and the EU had been prepared with Netanyahu himself.

The domestic political repercussions of a ceasefire for Netanyahu were made clear when his national security minister, Itamar Ben-Gvir, told the prime minister that his party, Otzma Yehudit (Jewish Power), would not vote with the coalition if the government agreed a ceasefire with Hezbollah.

“We will not abandon the residents of the north. Every day that this ceasefire is in effect and Israel does not fight in the north, Otzma Yehudit is not committed to the coalition,” Ben-Gvir said at a party meeting.

The leader of the opposition Democrats party, Yair Golan, also argued against committing to a three-week ceasefire, saying Israel should initially agree to a truce of a few days to see how well it was enforced.