Lebanon and Israel resumed US-mediated negotiations over their disputed maritime border on Tuesday after a months-long hiatus, in efforts to clear the way for offshore oil and gas exploration.

The talks, between countries still technically at war, kicked off at the UN base in the town of Naqura in southern Lebanon, the National News Agency said.

Washington said on Friday they were to be brokered by US diplomat John Desrocher, and called the resumption of talks "a positive step towards a long-awaited resolution".

Lebanon and Israel last year took part in indirect US-brokered talks to discuss demarcation.

But those talks stalled after Lebanon demanded a larger area, including part of the Karish gas field, where Israel has given exploration rights to a Greek firm.

The talks last year were supposed to discuss a Lebanese demand for 860 square kilometres of territory in the disputed maritime area, according to a map sent to the United Nations in 2011.

But Lebanon then said the map was based on erroneous calculations and demanded 1,430 square kilometres more territory further south, including part of Karish.

"The discussion will start from where we left it off,” a source at the Lebanese presidency told AFP on Tuesday.

He said both Israel and Lebanon had demanded a different demarcation line.

"We don’t accept the line they’ve proposed, and they don’t accept ours, so we’ll see what the mediator suggests.”

Last month, President Michel Aoun on Thursday demanded Israel halt all exploration in Karish until the dispute was settled.

In February 2018, Lebanon signed its first contract for offshore drilling for oil and gas in blocks 4 and 9, 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.

Lebanon’s government stepped down after a massive blast at Beirut’s port in August 2020, but deeply divided politicians have been unable to form a new cabinet ever since.

Lebanese politicians hope that commercially viable hydrocarbon resources off Lebanon’s coast could help lift the debt-ridden country out of its worst economic crisis in decades.