"A nuclear Iran governed by a radical Shiite cleric that possesses not just nuclear weapons potentially but the missiles that could deliver those weapons far away is an unacceptable risk, not just for Israel, not just for the United States, but for the world," Rubio told a joint news conference with Israeli Prime Minister Benjamin Netanyahu.

"That's why the president continues with a campaign of maximum pressure," Rubio said of President Donald Trump.

"There will continue to be maximum economic pressure on Iran until they change course."

Netanyahu, who has long warned of a threat from Iran, in June fought a war during which the Israeli military targeted both nuclear and conventional military sites and killed Iranian nuclear scientists.

The strikes came as Trump was pursuing diplomacy with Iran, but the US president soon shifted and ordered US bombers to attack key Iranian nuclear sites.

"The decision by President Trump to target the nuclear facilities of Iran was not merely a militarily wise thing to do," Netanyahu said.

"It was also a message to the entire world that the United States acts to defend its interests and defend its allies, and America has no better ally than Israel," he said.

Iranian officials, who have insisted its nuclear programme is for peaceful purposes, say more than 1,000 people were killed in the 12-day war.

Iranian drone and missile barrages killed at least 28 people in Israel during the war, according to official figures.