An influential Israeli rabbi has called for prayers for Iran's destruction, a week after Prime Minister Benjamin Netanyahu appeared to court his support for a possible attack on a nuclear programme Israel sees as an existential threat.

The sermon by Rabbi Ovadia Yosef added to a flurry of recent rhetoric from Israeli officials that has raised international concern that Israel, widely believed to be the Middle East's only atomic power, might attack Iran's nuclear facilities.

"(When) we ask God to 'bring an end to our enemies', we should be thinking about Iran, those evil ones who threaten Israel. May the Lord destroy them," Yosef was quoted as saying by Israeli media on Sunday.

Last week, Netanyahu sent his national security adviser to brief Yosef, 91, on Iran's nuclear activities in what was widely seen as an effort to win his backing for any future military strike, possibly before the U.S. presidential vote in November.

Yosef, a former Israeli chief rabbi, is the spiritual leader of the ultra-Orthodox Shas party, a key member of Netanyahu's governing coalition.

Netanyahu is frustrated that Western diplomacy to try to force Iran to rein in its programme has so far proved fruitless.

He said on Friday that Iran, whose leaders have threatened Israel's destruction, had made "accelerated progress towards achieving nuclear weapons".

Yosef issued his call in a sermon late on Saturday in which he said Iran should be included in a traditional Jewish New Year blessing next month over food in which God is asked to strike down Israel's enemies.

Netanyahu's security cabinet, which Israeli officials have said is divided over the question of launching a go-it-alone attack on Iran, includes a Shas minister as one of its eight members. Iran says it is enriching uranium for peaceful purposes.

Yosef wields significant influence over Shas's lawmakers, who seek his guidance on policy.

In the past, the Baghdad-born Yosef has stirred controversy by likening Palestinians to snakes, calling for Palestinian President Mahmoud Abbas to "perish from this world" and describing non-Jews as "born only to serve us".

But he has also spoken out in favour of Israel ceding occupied land for peace with the Palestinians in order to end conflict and save Jewish lives.