Israeli Prime Minister Benjamin Netanyahu has appointed a former military chief as the country's new defence minister.
Moshe Yaalon, a former army commando, has said Iran's suspect nuclear programme is Israel's top security concern.
He has been vague about whether Israel might carry out a military strike on Iran.
Minister Yaalon also has voiced scepticism about the chances for reaching peace with the Palestinians.
Mr Yaalon, widely known by his nickname "Bogie", was Israel's military chief from 2002 to 2005.
He oversaw Israel's army operations during the years of the second Palestinian uprising when Palestinian bombers killed Israeli civilians and Israel's army conducted military incursions into Palestinian cities.
Mr Yaalon also prepared Israel's military for the country's 2005 withdrawal from Gaza.
He did not support the decision to remove Israel's military installations and settlements from the Palestinian territory, and retired shortly before the withdrawal took place.
After retiring, Mr Yaalon briefly served as an expert with the Washington Institute for Near East Policy.
For the past four years, Mr Yaalon served as both vice premier and strategic affairs minister in Israel's outgoing government.
In those positions, Mr Yaalon was a member of Mr Netanyahu's Security Cabinet, which dealt with sensitive matters and played a leading role in monitoring Iran's nuclear programme.
Israel believes that Iran is trying to develop a nuclear weapon, a charge that Iran denies.