The Argentina submarine that vanished 12 days ago sent a final, desperate message reporting a short-circuiting battery and fire onboard, the Argentine Navy said Monday.

Enrique Balbi, a spokesman for the Argentine Navy, told reporters that in it the ARA San Juan's last message, the vessel’s captain said water had entered through the snorkel when the sub was charging batteries.

He said the water entered through the ventilation system to a battery connection tray in the prow and “caused a short-circuit and the beginning of a fire, or smoke without flame.”

SEARCH INTENSIFIES FOR ARGENTINA'S SUB WITH 44 CREW MEMBERS AS OXYGEN SUPPLY MAY BE RUNNING LOW

Balbi said the captain later communicated via satellite phone that the problem had been contained.

“They had to electrically isolate the battery and continue sailing underwater to Mar del Plata using another battery circuit,” he added.

The San Juan, a German-built diesel-electric TR-1700 class submarine, was last heard from Nov. 15.

Hopes for survivors have been largely crushed by reports of an explosion detected near the time and place the sub went missing.

Since then, there have been no signs of the sub or debris despite an intensive multinational search. Experts have said the 44 sailors aboard had only enough oxygen to last up to 10 days if the sub remained intact but submerged.

The navy said last week that, before the submarine went missing, the captain reported an electrical problem in a battery compartment and the vessel was ordered to return to its base in the coastal city of Mar del Plata, about 250 miles southeast of Buenos Aires.

The vessel was commissioned in 1985 and was most recently refitted in 2014.

In his first public comments since the sub went missing, Argentine President Mauricio Macri promised an investigation into the condition and age of the vessel.

“The disappearance and current search for the ARA San Juan submarine has touched all Argentines,” he said, according to Sky News. “It’s a difficult moment for all but, obviously, especially for the families of the 44 crew members.”

He continued: “I’m here to guarantee you that we will carry on with the search, especially now that we have the support of all the international community.”

The Navy says more than a dozen countries are still helping to search for the sub in the area where the explosion was recorded, about 250 miles off the coast of Argentina.

Balbi said a Norwegian ship carrying the U.S. Navy’s underwater remotely operated vehicle and its pressurized rescue module was expected to arrive to the search zone on Monday.

The Associated Press contributed to this report.