A top aide to Iran's Supreme Leader warned the United States on Tuesday against designating the elite Revolutionary Guards as a terrorist group, saying Tehran has "all options on table," news agency ISNA reported."The Americans are supporting Daesh (Islamic State). That’s why they are angry with the Revolutionary Guards. But they are too small to be able to harm the Revolutionary Guards," Ali Akbar Velayati, the top adviser to Iran's Supreme Leader Ayatollah Ali Khamenei, was quoted as saying by ISNA."Whatever they do we will take reciprocal measures. We have all options on the table," he added.