NASA released a statement Tuesday on the Titan, saying it remains "hopeful the crew will be found unharmed."

"NASA’s Marshall Space Flight Center had a Space Act Agreement with OceanGate, and consulted on materials and manufacturing processes for the submersible. NASA did not conduct testing and manufacturing via its workforce or facilities," the agency said.

-ABC News' Gina Sunseri

The U.S. Navy said it's sending to the search site experts and equipment "designed to provide reliable deep ocean lifting capacity for the recovery of large, bulky, and heavy undersea objects."

The equipment, which can lift up to 60,000 pounds, and the experts will arrive in Canada Tuesday night, the Navy said.

National Security Council spokesperson John Kirby said earlier Tuesday that the Navy was"on standby" to help with the search for the missing submersible, because the Navy has "some deep-water capabilities that the Coast Guard wouldn’t necessarily have."

President Joe Biden is "watching events closely," Kirby said, adding that Biden and the White House offer their thoughts "to the crew onboard, as well as to the -- what is no doubt -- worried family members back on shore."

Three U.S. Air Force C-17 cargo aircraft will be transporting commercial equipment from Buffalo, New York, to Newfoundland, Canada, to help with the search efforts, according to a U.S. official.

-ABC News' Luis Martinez

Efforts to locate the missing submersible are ongoing, and the "complex" search covers an area larger than the state of Connecticut, Coast Guard Capt. Jamie Frederick said at a news conference Tuesday.

Crews are scouring the ocean 900 miles east of Cape Cod and 400 miles south of St. John's, Canada, he said.

The missing five-person crew on the submersible has about 41 hours of oxygen left, Frederick noted.

"We will do everything in our power to effect a rescue," Frederick said.

"We have a group of our nation's best experts," he said, and once the sub is located, "those experts will be looking at what the next course of action is" to rescue the crew members.

"Our thoughts and prayers are with the crew and their families and their loved ones," Frederick added.

A senior U.S. Navy official confirmed to ABC News that an underwater acoustic detection system heard on Sunday what was likely the implosion of the Titan submersible. The information was immediately shared with the U.S. Coast Guard on Sunday and analysis continued afterwards.

"The U.S. Navy conducted an analysis of acoustic data and detected an anomaly consistent with an implosion or explosion in the general vicinity of where the Titan submersible was operating when communications were lost," the senior official told ABC News in a statement. "While not definitive, this information was immediately shared with the Incident Commander to assist with the ongoing search and rescue mission."

According to the official, "This information was considered with the compilation of additional acoustic data provided by other partners and the decision was made to continue our mission as a search and rescue and make every effort to save the lives on board.”

Separately, a U.S. defense official said an analysis of the “banging” noises picked up by sonar buoys were not from the missing submersible but were either natural ocean sounds, biological noises or noises associated with the surface response vessels.

-ABC News' Luis Martinez