Lebanon's armed Hezbollah group issued a video on Sunday showing vessels involved in the Israeli offshore oil and gas industry and warned against "playing with time", underlining its threat of military escalation amid maritime border demarcation talks.
Lebanon and Israel are locked in US-mediated negotiations to delineate their shared maritime border that would help determine which oil and gas resources belong to which country and pave the way for more exploration.
Lebanese officials have said they are optimistic that this round of talks can result in a deal after years of on-and-off indirect negotiations, but Hezbollah has warned it is ready to prevent Israel from extracting hydrocarbons should Lebanon not be allowed to do so.
Israel and Hezbollah fought a month-long war in 2006 and have traded fire on several occasions since but have avoided a large-scale confrontation.
Sunday's video, which also contains a rare glimpse of Hezbollah weaponry, was broadcast on the group's Al-Manar TV station hours before the US official mediating the maritime dispute, Amos Hochstein, was scheduled to meet Lebanese officials in Beirut.
It was issued by Hezbollah's War Media that the group uses to broadcast footage of military operations and battles, and contains images of ships involved in drilling for and extracting hydrocarbons, along with what appear to be their coordinates.
The video begins with the words of Hezbollah leader Hassan Nasrallah during a recent speech in which he warned that "playing with time is not useful" on the maritime issue.
"The message is a serous threat," a top Al-Manar correspondent said on Twitter.
A statement on Saturday by the US State Department said Hochstein's Beirut visit would aim to facilitate talks on the maritime boundary.
"Reaching a resolution is both necessary and possible, but can only be done through negotiations and diplomacy," it said.
A senior Israeli official, speaking to Reuters on condition of anonymity, said Hochstein would represent a new Israeli proposal that "includes a solution that would allow the Lebanese to develop the gas reserves in the disputed area while preserving Israel's commercial rights".
If this reaches agreement, it would entail "some drilling there" by the Lebanese, the Israeli official said without elaborating.
"The offer that has been relayed is a serious proposal that can transform Lebanon from a country of economic ruin and energy crises to a natural gas-producing country, by enabling it to cultivate this resource," the official said.