Lebanon and Israel kicked off a third round of sea border talks Wednesday under US and UN mediation to allow for offshore oil and gas exploration.
The delegations met under tight security at the headquarters of the UN peacekeeping force (UNIFIL) in the Lebanese border town of Naqoura, the National News Agency said.
Lebanon and Israel in early October said they had agreed to begin the negotiations in what Washington hailed as a "historic" agreement.
The first two rounds of talks were held on October 14 and 28-29.
The negotiations are meant to focus on an 860-square-kilometer disputed sea area according to a map registered with the United Nations in 2011.
But Lebanon has now demanded an additional area of 1,430 square kilometers further south, Lebanese energy expert Laury Haytayan said, characterizing the new phase of talks as a "war of the maps.”
She said the additional area extends into part of the Karish gas field which Israel has assigned to Greek firm Energean for exploration.
An Israeli source close to the talks said, meanwhile, Israel has demanded that the sea frontier be moved further north, deeper into areas claimed by Lebanon.
"The Israeli delegation itself presented a line that is north of the border of the dispute, and clarified that no talks will be held on a line that is south of the border of the dispute," the source said.
The head of the Israeli delegation, energy ministry director general Udi Adiri, earlier this month in a letter to Energean said discussing any areas outside the initial disputed area was out of the question.
"There is no change, and no perspective of change about the status of the Israeli commercial waters south of the disputed area, including of course, Karish and Tanin" gas fields, Adiri wrote in a letter to CEO Shaul Tzemach.
In February 2018, Lebanon signed its first contract for offshore drilling for oil and gas in Block 9 and Block 4 with a consortium comprising energy giants Total, ENI and Novatek.
Lebanon in April said initial drilling in Block 4 had shown traces of gas but no commercially viable reserves.
Exploration has not started in Block 9, part of which lies in the disputed area.