US military forces prepared to send more muscle to the scene of a stand-off with Somalia pirates holding an American hostage on a lifeboat in the Indian Ocean on Friday.
Tensions mounted on the high seas with both the pirates and the US Navy promising to move in reinforcements while an American captain stayed captive to the pirates as the saga approached its third day.
Four pirates on Wednesday hijacked the Maersk Alabama aid ship before being overpowered by the unarmed American crew and ousted from the 17,500-tonne Danish-operated container ship.
More naval ships were to join within 48 hours the destroyer USS Bainbridge that arrived overnight to help secure the release of the American, US defense officials said. "The safe return of the captain is the top priority," Defense Secretary Robert Gates told reporters in Washington.
The reinforcements were coming from naval forces already deployed in the wider region, including a counter-piracy task force out of Bahrain, officials said. "There's more naval assets being moved south from where they are towards where the (USS) Bainbridge is currently engaged in its activity with this pirate ship," an official with the US Central Command, speaking on condition of anonymity, told AFP.