As Israel steps up a campaign to muster support for waging war on Iran, the UN nuclear watchdog chief says the knowledge of Iranian nuclear scientists cannot be bombed.

In an interview with Newsweek, Director-General of the International Atomic Energy Agency, Mohamed ElBaradei, addressed Israeli threats of a potential unilateral strike on Iranian nuclear facilities.

When asked how keeping a military option on Iran's nuclear issue would affect matters, ElBaradei said, "there is no military solution. There is only a diplomatic solution [to Iran's nuclear dispute]."

"Israeli President Shimon Peres made the point that you cannot bomb the knowledge [of Iranian nuclear scientists]," explained the IAEA chief.

Israeli officials and military commanders have on many occasions threatened to launch military strikes on Iranian nuclear facilities -- which Iran says are being run under its obligations to the Nuclear Non-Proliferation Treaty (NPT).

The White House has so far made a strong stand against an Israeli strike on Iran. However, Israeli Prime Minister Benjamin Netanyahu attempted to sway US officials on the issue in his recent visit to Washington.

ElBaradei's warning came after US Defense Secretary Robert Gates revealed on Friday that US President Barack Obama had ordered the Pentagon to rejuvenate "contingency plans" for a military option on Iran.

Moving to the issue of confidential documents on Iran's nuclear activities -- supplied by the Americans to the IAEA -- ElBaradei said the agency is obliged to protect the identity of its sources.

"A lot is in documents which we cannot share with the Iranians because of the need to protect sources and methods. Iran says, how can I tell you if it is fake or authentic if I am not getting a copy?" ElBaradei told Newsweek.

The "alleged studies of weaponization", attributed to Tehran by countries such as the United States, accuse Iran of pursuing a "green salt project, high explosives testing, and the missile re-entry vehicle project."

Iran says the accusations have been based on "forged" data, asking the IAEA to provide it with genuine copies of the documents, saying the documents will allow the country to study and respond to the allegations appropriately.

The agency maintains it is not "in a position" to do so -- as the Vienna-based watchdog only possesses digital copies of the documents.

The IAEA, however, has called on the 10 countries in possession of the evidence related to the allegations to share it with Iran.