In September 2011, the U.S. administration secretly transferred 55 so-called bunker-buster bombs to Israel.

The 5,000-pound bombs conceivably put Israel in the position to attack Iran's buried nuclear facilities, French media reports, citing anonymous source at investigation services.

However, the U.S. demands that Israel should not start hostilities against the Islamic Republic without counseling Washington first. At current stage, U.S. and Great Britain urge to toughen sanctions against Iran without resorting to hostilities.

Iran, in the meantime, is threatening to administer a return strike on Israeli nuclear facilities, according to MIGnews.