A French robot that can dive to a depth of 6,000 metres is due to arrive in the North Atlantic late on Wednesday and join the search for the missing submersible, Titan.
The unmanned craft, called Victor 6000, has remotely controlled arms that can be used to cut cables or perform other manoeuvres to release a vessel that has got stuck.
The wreck of the Titanic, which the Titan was heading towards, lies at a depth of about 3,810 metres.
Victor 6000 is operated by a 25-strong crew. “We can work non-stop for up to 72 hours – we don’t need to stop at night,” said Olivier Lefort from Ifremer, a state-run French research institute that operates the robot.
Titan has been missing since Sunday
While the vehicle could not lift Titan to the surface on its own, it could help to hook it to a ship on the surface.
“Victor is able to do visual exploration with all the video equipment it has”, Mr Lefort said.
“It is also equipped with manipulating arms which could be used to extricate the sub, such as by sectioning cables or things that would be blocking it at the bottom.”
The robot is currently aboard a French research vessel.
“We are close, we have to go,” Mr Lefort said, describing the decision to offer help as the “logic of seafarers”.
He was part of the team that located the wreck of the Titanic in 1985 with American underwater archaeologist Robert Ballard.
A 25-strong crew controls the Victor 6000
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Underwater noises in hunt for Titan – what do they mean for search?
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Remotely operated vehicle (ROV) searches are already under way close to where Titan is thought to have gone missing, the US Coast Guard has said.
Overnight, there were reports of “banging”, but two senior Department of Homeland Security officials have told NBC News, Sky’s partner network, that it’s more accurate to talk of “sounds” and “noises”.
Canadian P-3 aircraft detected underwater noises and ROV searches are being directed to the area of the sounds, the Coast Guard has said.