An Israeli official says Prime Minister Benjamin Netanyahu is exploring the possibility of bringing a hard-line party into his coalition.

The official says that Netanyahu and Avigdor Lieberman agreed Wednesday to form teams to work out the details of an alliance. Israeli media said that Netanyahu had offered Lieberman the post of defense minister, currently held by Moshe Yaalon.

The official, who spoke on condition of anonymity because he was not authorized to discuss the matter, could not confirm the reports.

Lieberman, who has been both an ally and rival of Netanyahu's, heads the ultranationalist Yisrael Beitenu party. Lieberman has held a number of Cabinet posts in the past, including stints as foreign minister.

Netanyahu is eager to expand his shaky coalition, which has a narrow one-seat majority in parliament.