"They [Lebanon] are announcing a tender on the gas field, including Block 9, which is ours by any definition," Lieberman said at a conference in Tel Aviv.
The Israeli minister said that the respectable companies participating in the tender were making a major mistake, as their involvement in the project contradicts any rules and practices.
Lebanon launched its first oil and gas production licensing auction in January 2017, opening five of ten of its Mediterranean blocks up for international bids.
Lebanon, together with Israel, Cyprus and Egypt, sits on the Levant Basin in the eastern Mediterranean, where new gas fields have been revealed in 2009. Two Lebanese offshore blocks now lie within a triangle of maritime territory claimed by Israel.