Mossad Chief Yossi Cohen warned on Monday that “Iran is threatening to cause heavy damage if the sanctions against it are not removed or eased.”

The Israeli spy-master was speaking in a rare public pronouncement at the annual Herzliya Conference, only hours before the International Atomic Energy Agency confirmed that Iran had breached the 300 kg limit of enriched uranium as stipulated by the nuclear deal.

Mr Cohen contrasted the increasing willingness of moderate Arab regimes to improve ties with Israel with Iran’s hostility to the Jewish state, adding: “In recent weeks, a series of attacks on energy installations and oil tankers took place. The debate over who is responsible is crucial but I can say with certainty that Iran is behind these attacks, which were authorised by the Iranian leadership and executed by the Revolutionary Guards.”

Mossad has also detected, according to Mr Cohen, Iranian plans stretching back many months to acquire new centrifuges to purify uranium. He did not detail any future Israeli plan to counter Iran, although he did speak at length about the operation last year in which Mossad purloined a large Iranian nuclear archive from Tehran.

“One of the main objectives of Mossad is to minimise, as far as possible, Iran’s influence on the region,” he said.

Earlier in the day Benjamin Netanyahu had spoken about Iran’s breach of the enriched uranium limits, saying that “Iran is progressing in a significant step towards nuclear weapons. When we reveled Iran’s secret nuclear archive, we proved that the nuclear agreement with Iran is based on a big lie.”

The Israeli Prime Minister also repeated his commitment that Israel would not allow Iran to develop nuclear weapons.

However, Israeli security officials admitted that at this point there is very little Israel can do to influence events as the initiative is now with the Trump administration, which has imposed new sanctions on Iran but does not seem to have a clear plan beyond that.

“To be honest, we don’t know what Trump’s Middle East policy is,” one senior Israeli officer said. Last year, President Donald Trump’s sudden announcement that he was withdrawing all US troops from Syria caused dismay in Israel, where the small American presence in eastern Syria is seen as a bulwark against further Iranian encroachment on Israel’s northern border. That decision has yet to be fully implemented.

Two weeks ago, the US seemed on the brink of attacking Iran after an American drone was shot down in the region but the attack was aborted at the last moment on President Trump’s orders.

Last week, a high-level meeting of Israeli, American and Russian national security advisors was held in Jerusalem, during which the US backed Israel’s demand that Iranian forces be pulled out of Syria. But it has become clearer in recent days that US National Security Advisor John Bolton has diminishing influence in the administration and there is no real pressure on Russia to try and enforce an Iranian departure.

Mr Netanyahu, the most vocal opponent of the Iran Deal, is naturally pleased with its gradual disintegration but those who advise him on security matters are less certain about what comes next.

Their concern is both over what happens if Iran brazens it out or if the leadership in Tehran agrees to come to the table and negotiate with the US, especially seeing how Mr Trump fawned on Sunday over the Korean dictator Kim Jong Un, another leader he once threatened with annihilation.