Iran has said to EU defence ministers that it will deploy missiles and chemical weapons in the Persian Gulf if it feels threatened by the United States.
Iranian naval forces are now inducting anti-ship missiles and anti-submarine warfare systems fearing a possible attack.
Iranian defence minister Admiral Ali Shamkhan told defence ministers of Britain, France and Germany in a secret private meeting outside Europe that the Iranian navy would be pro-active in the entire Persian Gulf region in case of perceived hostility.
Admiral Shamkhan, however, clarified that Iran would not target neutral allies or neutral countries.
Iran believes that to deter its nuclear programme, the US is considering a naval and economic blockade against it as a prelude to war.
Any such act would be considered hostile by Teheran, even if it were non-military in nature, diplomatic sources said.
Iranian missions abroad have already conveyed this new position to neighbouring countries.