The implication seems to be that Iran will act out this threat even if it is threatened by the US, as he was speaking in reaction to the news that the US was deploying missile defenses around the Persian Gulf.
In other news, the Organization of the Islamic Conference has made yet another special holiday in support of Palestinian Arabs, taking an Iranian idea to make January 18th into an annual "Day of Gaza and Resistance."The illustration to that story in the print edition of the Tehran Times couldn't possible be construed as anti-semitic, could it?