The head of the search operation for the missing Titan submersible has said that it is still an active search and rescue mission.

That is despite US Coast Guard estimates that the air supply in the vessel would run out at 12.08pm UK time on Thursday.

Rear Admiral John Mauger told Sky News: “We continue to keep the crew members and families in our thoughts.”

But he insisted this is “still an active search and rescue right now”, and added: “Conditions for the search and rescue are favourable right now.”

The vessel disappeared on Sunday in the Atlantic Ocean, some 435 miles south of Newfoundland, Canada, during an expedition dive to see the wreck of the Titanic.

Ships, planes and underwater craft from multiple countries have been deployed to the area with rescuers searching a remote part of the Atlantic Ocean more than twice the size of the US state of Connecticut in waters as deep as 4,020m (13,200ft).

The desperate search for the submersible has included investigating underwater noises amid speculation it could be coming from the missing vessel.

The vessel – operated by the US-based firm OceanGate – had five men on board when it went missing: British billionaire Hamish Harding, British businessman Shahzada Dawood, his son Suleman Dawood, OceanGate’s US-based chief executive and founder Stockton Rush and French submersible pilot Paul-Henri Nargeolet.