Lebanese President Michel Aoun said on June 26 that Israel refused to agree to a final maritime border between the two countries, a month after Lebanon began exploring for its first offshore oil and gas reserves.

Lebanon has an unresolved maritime border with Israel that involves a triangular area of sea of about 860 sq km (330 sq miles). The area extends along the edge of three of its 10 offshore energy blocks.

In February, Lebanon signed its first E&P agreements for offshore Blocks 4 and 9 with a consortium of France’s Total, Italy’s Eni and Russia’s Novatek. Block 9 contains an area of water claimed by both Israel and Lebanon, but the consortium has said it has no plans to drill in the disputed part.

“Israel still refuses the demarcation of the maritime borders near the Exclusive Economic Zone where exploration for oil and gas has begun,” Aoun said on Twitter.

Lebanon, which began its first offshore exploration in May, is on the Levant Basin in the eastern Mediterranean, where a number of big subsea gas fields have been discovered since 2009 in Cypriot, Israeli and Egyptian waters.

U.S. officials have been mediating between Lebanon and Israel about the maritime border dispute.

Israel’s energy minister said earlier this month that new ideas proposed in the U.S. back-channel mediation raise the prospect of a partial deal this year.

Offshore