This coalition offers Netanyahu a 66 legislators government, widening his majority in the 120- member parliament. Previously, his government only had 61 legislators.
 
Lieberman's return to office -he was previously foreign minister- has raised questions at home and abroad given his past criticism of Israel's Arab minority, U.S.-sponsored peace talks with Palestinians and regional powers Egypt and Turkey.
 
Palestinian officials said that with Lieberman, who lives in a settlement in the occupied West Bank, back in the cabinet as defense minister prospects for reviving statehood negotiations that collapsed in 2014 had grown dimmer.
 
Speaking in English, as a message to the global community, Lieberman promised a “responsible and reasonable” policy. However, in the past he once famously threatened to bomb Egypt's Aswan dam and has called for the assassination of Hamas Islamist leaders in Gaza.
 
“At the end of the day my intention (is) to provide security and of course all of us we have a commitment, strong commitment, to the peace, to the final status agreement (with the Palestinians)” said Lieberman.
 
Several former Israeli defense ministers have criticized Lieberman's appointment to the sensitive post, citing the politician's relative lack of military experience.
 
It is possible the newly formed government has already lost one legislator as Orly Levi-Abekasis, has said she is leaving the party and would vote independently in parliament. Nevertheless, Levi-Abekasis's spokesman said on Wednesday she is still formally a member of Yisrael Beitenu as procedural issues had yet to be finalized.
 
Yisrael Beiteinu  will become the sixth party in Netanyahu's religious-nationalist coalition. Netanyahu was elected for a fourth term last year. The deal prompted Moshe Yaalon, a Likud member and former general, to quit as defense minister in protest on Friday.