The vessel was found at a depth of more than 800 metres (2,600 feet), the Navy tweeted, confirming the vessel had imploded.
Ocean Infinity, a United States company specializing in deep water search and recovery, began looking for the ARA San Juan in September, using autonomous underwater vehicles operated by a team on board its ship Seabed Constructor, the firm said.
Rescuers found the San Juan just two days after families of the missing sailors held a commemoration event marking a year since the submarine disappeared.
He said the hull was "totally deformed, collapsed and imploded" and debris was scattered over an area of about 70m.
The crew had been ordered to return to Mar del Plata on the country's east coast.
After submarine went missing, the president promised a full investigation.
Argentine police investigating the sub's disappearance raided naval bases in January. During the US$12 million retrofitting, the vessel was cut in half and had its engines and batteries replaced.
Experts have said that refits can be hard because they involve integrating systems produced by different manufacturers, and any mistake during the cutting phase can put the safety of the ship and crew at risk.
It was only several days into the tragedy that navy officials acknowledged the old, German-built submarine had reported a problem with its batteries in its final communication of November 15. The captain later communicated that it had been contained.
Almost 10 days later, the navy confirmed there had been an explosion on board, which experts said was likely linked to the battery problem.
Argentina gave up hope of finding survivors from the vessel after an global search, aided by 18 countries, ended without success. A rescue mission to locate the ARA San Juan was abandoned after two weeks previous year.
"Our thoughts are with the many families affected by this bad tragedy".
The discovery came the day after a somber ceremony, which Macri attended, at the San Juan's Mar del Plata base on the first anniversary of its disappearance.
No distress call was issued, with 18 countries involved in the search mission launched on November 16 a year ago.
The company unsuccessfully searched for the Malaysia Airlines plane that disappeared in 2014 over the Indian Ocean.