The US Coast Guard will deploy additional resources to continue the search for the missing Titan submersible.

"As long as there's an opportunity for survival, we will continue," says John W. Mauger, commander of the US Coast Guard First District.

Rescue workers are racing to beat a rapidly closing oxygen window as they hunt for the missing craft near the wreck of the Titanic, after noises detected by sonar raised hopes the five people onboard are still alive.

Mauger said: "We're working very hard as part of an international effort, as part of a unified command, with the US Navy, with the Canadian armed forces, the Canadian Coast Guard, and private enterprise to bring as many assets to bear, as many capabilities to bear at the search site to conduct both a thorough, air, surface, and subsea surface search."

"We had a P-3 aircraft, an Aurora aircraft, flying yesterday that had sonobuoys. The sonobuoys detected noise in the water. We don't know the source of that noise, but we've shared that information with Navy experts to classify it. In the meantime, what we've done is reprioritize the two remote-operated vehicles that we have searching in the water and the one surface vessel that has sonar capability at the surface of the water in the area of those noises to see if we can locate the source of those noises and locate the people in the submersible," he added.

"This is an incredibly complex site there. You have to remember that it's the wreck site of the Titanic, so there is a lot of metal and different objects in the water around this site. That's why it's so important that we've engaged experts from the Navy that understand the science behind noise and can classify or give us better information about what the source of that noise may be," he explained.

"As long as there's a (sic) opportunity for survival we will continue to work with this broad unified command to bring every resource to bear on the search. Over the course of the next 24 hours, we're going to bring additional vessels, additional remote-operated vehicles, and we're going to continue to fly in the air. So we'll continue to look," he said.