Program Note: Tune in tonight to hear more on the situation on AC360° at 10 p.m. ET.

Attackers hijacked the Maersk Alabama, shown here, formerly known as the Alva Maersk.

Chris Lawrence
CNN Pentagon Correspondent

The USS Bainbridge is "within a few hundred yards" of the lifeboat holding Richard Phillips, the kidnapped American captain of the Daemsk Alabama, a US defense official confirms.

The pirates have larger "mother ships" nearby. The Navy is aware of their locations and doing surveillance.

The USS Halyburton, a frigate with choppers and guided missiles, is also "in the area" now, which I took to mean it's not right there on the scene but is in the general area.

The amphibious USS Boxer, which has choppers and a hospital unit, is still "a day or two away."