"I tell the prime minister of the Zionist regime to practice swimming in the Mediterranean because soon you will have no choice, but flee into the sea," Brigadier-General Hossein Salami said, according to the ultraconservative news website Fars news.

Speaking at a rally of the volunteer Basij militia in the central Iranian city of Isfahan, Salami said Israel could be destroyed by Iran's Lebanese ally Hezbollah.

"They are not at the level of being a threat for us, Hezbollah is enough for destroying them," he said.

Iran does not recognise Israel, and opposition to the Jewish state has been a central tenet of its government since the 1979 revolution.

Its officials regularly warn that Israel will soon cease to exist, although they are usually careful to indicate that this will not be due to a direct attack by Iran.

"In 25 years' time, with the grace of God, no such thing as the Zionist regime will exist in the region," said supreme leader Ayatollah Ali Khamenei in 2015, which has become a frequently-used prediction among hardliners.

The presence of Iranian troops and equipment in Syria has served to dial up the tension between the two countries.

In September Netanyahu accused Iran at the UN general assembly of still trying to build nuclear weapons and vowed he would "never let a regime that calls for our destruction to develop nuclear weapons. Not now, not in 10 years, not ever."