Israel rejected Thursday Lebanese changes to a draft US-brokered proposal demarcating a maritime border with Lebanon, putting the fate of a deal for joint gas production in limbo. 

Throwing into doubt years of diplomatic efforts to enable both enemy countries to extract gas in or around a disputed Mediterranean prospect, Prime Minister Yair Lapid instructed negotiators to turn down Lebanon’s requested modifications, according to a senior Israeli official. 

Calling Beirut’s new demands “significant,” the official added that any further negotiations would cease permanently if Lebanon's Iran-backed Hezbollah movement threatens or attacks Israel's Karish gas rig, without providing further details for the volte-face. 

If Lebanon-based Hezbollah tries to strike the Karish offshore gas field or threaten Israel, the talks would “end permanently, and [the terror group’s leader] Hassan Nasrallah will have to explain to Lebanese civilians why they don’t have gas rigs or an economic future,” the official noted.

The official said that Lapid emphasized that he would not compromise on Israel’s economic and security interests even if it meant that there would be no deal in the near term.

The statement cast doubt on the viability of a deal that, only days ago, Israeli officials were speaking of it as a foregone conclusion. 

On Saturday, the Biden administration’s energy envoy Amos Hochstein presented what was seen as the final proposal aimed at addressing competing claims over offshore gas fields in the Mediterranean Sea. 

On Thursday, Lebanon’s caretaker prime minister said the deal with Israel would avert a war in the Middle East. “We are avoiding a definite war in the region,” Najib Mikati said.