Report: Iran arming warships with short-range missiles

The missiles being moved onboard Iranian naval vessels have an effective range of between 200 to 300km, Iranian Revolutionary Guards commander Ali Fadavi told the semi-official Mehr news agency on Friday. 

At that range, those missiles would be able to strike targets in the Straits of Hormuz or the Sea of Oman from the Iranian coastline, Fadavi said. 

U.S. Navy commanders have also beefed up their Persian Gulf fleet, to defend against any potential Iranian attack. 

The Navy is doubling the number of its mine-hunting ships patrolling the key waterway. In the past, the Iranian navy has peppered its coastal waters with sea-based mines, as a way to protect its shores from attack. 

Navy leaders have also outfitted its destroyers and cruisers in the region with powerful Gatling guns. The weapons are ideal for taking out the small, fast-moving patrol boats the Iranian navy commonly uses to patrol the strait. 

But news of the new weapons come a day after Chief of Naval Operations Adm. Jonathan Greenert told reporters that things have been calm along the Straits over the past few months. 

"Things have been relatively speaking quiet in that regard," Greenert said during a Thursday briefing at the Pentagon. 

There have been instances were Iranian warships have sailed close to U.S. Navy vessels moving through the Straits, according to Greenert. 

"But frankly, that hasn't happened ... in the last couple of months," the four-star admiral said. "Operations have been predictable, and ... in accordance with the international rules." 

Earlier this year, Iranian military leaders threatened to block off the Straits to American Navy and commercial ships, claiming any U.S. vessel attempting to cross the waterway could be attacked. 

Iran eventually backed off those threats after an intense round of diplomatic talks between Tehran and Western powers, but tensions continue to run high in the region.

Tehran has used the Straits, the main entry point into the Persian Gulf, as a bargaining chip in negotiations with world powers over the country's controversial and highly-secretive nuclear program. 

Iran's aggressiveness in the Straits has been seen as a check to U.S. and Israeli threats of military action against the country's nuclear program. 

So far, ongoing negotiations between Iran and the P5+1 group -- the the five permanent United Nations Security Council members and Germany -- over the nuclear program have yielded little results.