Israeli Prime Minister Benjamin Netanyahu said "good riddance" on Tuesday after Iranian Foreign Minister Mohammad Javad Zarif abruptly announced his resignation.
"Zarif is gone. Good riddance," Netanyahu said of the lead negotiator of Iran's landmark 2015 nuclear agreement with major powers that he had bitterly opposed.
"As long as I am here, Iran will never acquire nuclear weapons," Netanyahu tweeted.
Iran denies any ambition to develop an atomic weapons capability and says its nuclear programme is for peaceful purposes only.
It refuses to accept the legitimacy of the Jewish state and has provided support to Palestinian and Lebanese militant groups that have waged war against Israel, making it Israel's number one enemy.
Netanyahu has pledged to stop Tehran from entrenching itself militarily in neighbouring Syria and Israel has carried out hundreds of air strikes against what it says are Iranian and Hezbollah targets there.
Iran is the main backer with Russia of Syrian President Bashar al-Assad in his country's nearly eight-year civil war.
