Israeli official say a deal has been reached to expand the coalition government by bringing in the ultranationalist Yisrael Beitenu party of Avigdor Lieberman.

According to the agreement reached on Wednesday, Lieberman will become the country's new defense minister.

Moshe Leon, a representative for Lieberman, says a deal will be signed later in the day. A government official confirmed both sides have reached an agreement. The official spoke on condition of anonymity under regulations.

The deal caps a tumultuous week of politics that began with Prime Minister Benjamin Netanyahu being expected to invite the moderate Labor Party before he chose Lieberman's ultranationalist party instead.

Lieberman, one of Israel's most polarizing politicians, will take over as defense chief in place for former military chief Moshe Yaalon, who resigned earlier this week.