The report, which was not sourced, came as US National Security Advisor Tom Donilon concluded two days of talks with Israeli leaders, which focused on Iran, amid mounting speculation that Israel will attack Iran in the coming months to prevent it from obtaining a nuclear arsenal.

Donilon met Monday with Israeli Defence Minister Ehud Barak, but apart from informing reporters that the meeting had taken place, the Israelis put out no statement.

A government official said Israel was trying to keep Donilon's visit 'low profile.'

The White House was scarcely more forthcoming, saying in a statement only that during the visit 'Mr. Donilon and his delegation addressed the full range of security issues of mutual concern.'

The issue of Iran's nuclear programme is expected to be the focus when Prime Minister Benjamin Netanyahu meets President Barack Obama in Washington on March 5.

Israel has consistently pushed for tougher sanctions against Iran, but its leaders have also not totally ruled out a military strike. In Cyuprus last week, Netanyahu said the sanctions targeting Tehran are so far not working.

The US is known to be opposed to any Israeli attack on Iran's facilities.

Chairman of US Joint Chiefs of Staff General Martin Dempsey told CNN that Washington believed an Israeli attack would be 'destabilizing' and would not achieve Jerusalem's long-term objectives.

Israel regards Iran is its biggest existential threat, because of its nuclear programme coupled with repeated statements by President Mahmoud Ahmadinejad and other Iranian leaders that the Jewish state should cease to exist.