Washington ( CNN ) -- A senior Iranian naval official says Iran is sending warships toward U.S. maritime borders to send a message , a move a U.S. defense official characterized as an announcement , not a deployment . `` Iran 's military fleet is approaching the United States ' maritime borders , and this move has a message , '' Adm. Afshin Rezayee Haddad said , the semiofficial Fars news agency reported Saturday . The plan , according to Fars , is a response to the United States beefing up its naval presence in the Persian Gulf . The U.S. 5th Fleet is based in Bahrain . Haddad said the Iranian fleet was under way and approaching the Atlantic Ocean `` via the waters near South Africa , '' a claim that has not been confirmed . It 's not the first time Iran has made such a threat , said the U.S. defense official , speaking on condition of anonymity . `` It 's important to understand that , at this point , we have an announcement not a deployment . They 've stated this aspiration before , '' said the defense official , speaking on condition of anonymity because of the sensitivity of the matter . In 2011 , Iran twice announced plans to send ships toward the U.S. maritime borders . `` Freedom of the seas does n't just apply to fish . It applies to all maritime nations , all navies , everywhere -- so long as they understand the responsibilities which come with that freedom , '' the defense official said . `` So if they chose to send their ships to the Atlantic , I 'm sure they wo n't be surprised to find many , many others already there . '' The Iranian navy is the smallest of its military forces , according to GlobalSecurity.org , which tracks defense and intelligence issues . In December : U.S. , Chinese warships come dangerously close . Barbara Starr reported from Washington ; Chelsea J. Carter wrote from Atlanta . CNN 's Sara Mazloumsaki contributed to this report .
Iran move is meant as a message , a senior Iranian naval official says . `` We have an announcement , not a deployment , '' a U.S. defense official says . The United States has been working with the Iranians to develop and test their own missile defenses in recent years. `` Freedom of the seas does n't just apply to fish , '' U.S. defense official says .