(CNN) -- The Iranians are coming! The Iranians are coming!
Well, OK, maybe not. But if a couple of vessels flying the colors of the Islamic republic do appear off American shores sometime soon, don't panic. Even if it happens -- something U.S. officials have called into question -- the point of any such voyage appears to be to make a public-relations splash.
"What this does is, to people who don't know anything about sea power, which is a fairly substantial number of people in the developing world, it looks like a major gesture," U.S. military analyst Anthony Cordesman told CNN. "Within Iran's sort of politics, it follows a long theme of Republican Guard and other statements that Iran can defeat the United States."
But Cordesman, who holds the Burke Chair in Strategy at the Center for Strategic and International Studies, said the reported Iranian flotilla -- led by an aging frigate the U.S. Navy once nearly sunk -- poses no risk to the world's biggest naval power.
"Deploying a military museum is not going to threaten to the United States," he said.
The semi-official Iranian news agency Fars quoted the head of Iran's navy over the weekend as saying an Iranian flotilla "is approaching the United States' maritime borders" as a response to the U.S. decision to beef up its naval presence in the Persian Gulf. Adm. Afshin Rezayee Haddad said the Iranian ships were nearing the southern tip of Africa en route to the Atlantic Ocean.
A U.S. military official, speaking on condition of anonymity, said there was no information to support the claim, and there was no other corroboration of the report from Tehran. Iran announced plans to send ships toward the U.S. maritime borders twice in 2011; neither deployment materialized.
But Iran's Press TV reported in January that the frigate Sabalan and the supply ship Kharg, which also carries helicopters, were headed to the Atlantic "to provide the safety of Iran's shipping lines in international waters and to provide training for the new recruits."
The 300-foot Sabalan went into service in 1972. It was heavily damaged in a skirmish with American forces in 1988, when U.S. warships were dispatched to protect international oil tankers during Iran's war with Iraq.
The announcement comes as Iran prepares to mark the 35th anniversary of the revolution that toppled Shah Mohammed Reza Pahlavi. The Pentagon sounded unfazed by the Fars report.
"Aspirations not new. Freedom of seas applies to all, so long as they understand responsibilities of that freedom," Rear Adm. John Kirby, the Pentagon's press secretary, posted on Twitter.
Most of Iran's navy is made up of small attack craft, about two dozen of which are armed with missiles, according to the authoritative Jane's Fighting Ships. Its biggest warships are the Sabalan and its four sister frigates, along with two smaller and lighter corvettes and 14 diesel-electric submarines.
Tehran previously dispatched ships to patrol the Gulf of Oman and Indian Ocean for Somali pirates, capturing 13 during a 2012 engagement. It also dispatched warships to the Mediterranean Sea via the Suez Canal in 2011 and 2012 -- moves billed as carrying messages of "peace and friendship" to the region, but which also tweaked the nose of regional foe Israel.
But the navy's main mission is to defend its home waters in the Persian Gulf and control the Strait of Hormuz. While it has the potential to attack its rivals in a hit-and-run fashion, "That's not the kind of force you can deploy outside the Gulf," Cordesman said.
"Iran can sort of make demonstrative gestures and sail in international waters off the U.S. East Coast, or West Coast for that matter," Cordesman said. "But it's not much more threatening than if somebody showed up in a rowboat."
CNN's Barbara Starr contributed to this report.