Israeli PM @netanyahu fired Defense Minister Yoav Gallant, the PM's Office announced, amid fears of an Iranian attack on Israel.
Israel Katz is said to replace him, according to the statement.
Netanyahu offered Gideon Saar the post of Foreign Minister, replacing Katz
Mr Netanyahu said a "crisis of trust" had developed between him and Mr Gallant.
He said there had been too many "significant gaps" between them over the management of Israel's wars.
"In the midst of a war, more than ever, full trust is required between the prime minister and defence minister," Mr Netanyahu said.
"Unfortunately, although in the first months of the campaign there was such trust and there was very fruitful work, during the last months this trust cracked between me and the defence minister."