A top US admiral has denied media reports that an aging warship will be serving as a floating base for special forces in the Gulf, saying the vessel would instead be used to help clear mines.

The USS Ponce, a 1970s-era amphibious transport ship, is undergoing an overhaul to support naval forces in the Middle East, said Admiral John Harvey, US Fleet Forces command chief, told reporters Tuesday.

But its primary mission is not to serve as a "mothership" for elite commandos, as reported by the Washington Post and other news outlets.

"I think they put two and two together and got 22," Harvey said when asked about the reports.

"It is not going over there as a special operating forces 'Deathstar ...Galactica' coming through the Gulf," Harvey said, referring to a sci-fi television series.

The upgrades to the USS Ponce grew out of a standing request from US Central Command, which oversees American forces in the Middle East, to help with efforts against potential mines in the Gulf, Harvey said.

Iran has threatened to shut down the strategic Strait of Hormuz in retaliation for US and European sanctions. In the 1980s, Tehran relied on mines to disrupt shipping in the area during its war with Iraq.

The Ponce can carry MH-53 helicopters and support patrol craft, the admiral said. Such aircraft and vessels are often used by special forces.

Confusion about the Ponce's mission may have been the result of a call for private bids to carry out the improvements to the ship, he said.

The procurement documents included references to upgrades that would make some spaces accessible to special operations forces.

Harvey said the revamped Ponce should be ready to sail to the Gulf by June.

The Navy hopes to develop a new line of ships in the coming years that would serve as floating bases, and the altered Ponce could serve as a "bridge" to the new vessels, Harvey said.