Two remotely operated vehicles have been deployed as part of the search effort.
The US Coast Guard says an active search and rescue operation is ongoing for the missing submersible near the wreck of the Titanic.
It disappeared on Sunday with five people on board.
Head of the search operation, Rear Admiral John Mauger, was asked if he though the oxygen on board had run out by now.
"We continue to keep the crew members and the families in our thoughts as we proceed with this search and rescue while we're cognisant of the time and we've factored in a lot of data and information into the search," he told Sky News.
The Canadian vessel Horizon Arctic has deployed an ROV that has reached the sea floor and began its search for the missing sub. #Titanic
— USCGNortheast (@USCGNortheast) June 22, 2023
"This is still an active search and rescue at this point and we're using the equipment that we have on the bottom right now, the remote operated vehicles to expand our search capability, and then also to provide rescue capability as well."
France are helping with the search. Victor 6000 is an unmanned robot that can dive deeper than other equipment at the site.
It has arms that can be remotely controlled to cut cables or perform other manoeuvres to release a stuck vessel, the machine’s operator said.
It's also been confirmed that two deepwater ROVs, or remotely operated vehicles, have arrived at the site with one having reached the sea floor.
The United States Coast Guard tweeted that the submersible attached to the Canadian vessel Horizon Arctic had reached the sea floor.
