Israel worries Iran will secure a windfall in sanctions relief in renewed nuclear talks but will not sufficiently roll back its bomb-making potential, Israeli Prime Minister Naftali Bennett said on Sunday.

Negotiators will convene in Vienna on Monday in a last-ditch effort to salvage a nuclear deal which the United States under then-President Donald Trump quit in 2018, reimposing sanctions on Iran. That led to breaches of the deal by Tehran, and dismayed the other powers involved.

Israel, which is not a party to the talks, opposed the original 2015 pact as too limited in scope and duration. Israeli leaders have long threatened military action against Iran if they deem diplomacy a dead end for denying it nuclear weaponry.

"Israel is very worried about the readiness to remove the sanctions and to allow a flow of billions (of dollars) to Iran in exchange for unsatisfactory restrictions in the nuclear realm," Bennett told his cabinet in televised remarks.

"This is the message that we are relaying in every manner, whether to the Americans or to the other countries negotiating with Iran."

Few expect a breakthrough in the talks as Iran's uranium enrichment activities have escalated in an apparent bid to gain leverage against the West.

Reporting by Reuters