The Argentinian Navy has said an acoustic event near the last known location of the the missing submarine is "consistent with an explosion".
The navy said on Wednesday it was investigating an unusual noise detected in the South Atlantic hours after it last communicated with the submarine, but refused to confirm whether it indicated an explosion.
The noise was observed around the time the ARA San Juan submarine sent its last signal last week.
Balbi told reporters Thursday that six teams were continuing to look for the missing submarine near the San Jorge Gulf, about 430 kilometres from the Argentine coast, CNN reported.
Friday, Balbi said he wouldn't entertain speculation about where the San Juan is, despite knowing roughly where the noise came from.
No sign of the Argentine submarine lost in the South Atlantic since November 15 has been found despite a massive global search effort, while families of the 44 crew members face the increasing likelihood that their loved ones will never return.
The ARA San Juan submarine stopped communication mid-last week, but the search for the missing sub grew more frantic over the weekend after it had failed to make contact or surface, as would be expected if it was distressed.
"Until we find the submarine and have all the information", Macri said on Friday, "we are not going to speculate on who is at fault". "Hopes were buoyed after brief satellite calls were received and when sounds were detected deep in the South Atlantic", according to the AP.
Image A major search is taking place for the submarine
The information about the explosion received on Thursday morning was consistent with a separate report received on Wednesday of an "acoustic anomaly" in the same area and around the same time the vessel gave its last signal, Balbi said. The submarine's captain had reported a battery failure before it vanished. "But at this point we have to think that if he's at the bottom, it's because he could not emerge".
Following the announcement of the apparent explosion, Mr Williamson said: "This has not just been an agonising time for Argentina, but for our whole worldwide community, and this news is truly devastating for everyone involved in this week's search and rescue operation". The countries contributed personnel, planes and boats.
However, family members of the crew criticized the rescue effort.
"I told the admiral that if they are responsible for what has happened to my brother, a national hero, and other crew, we expect that they pay for this", Rodriguez said.
"How can you lose a 60-metres long navy vessel, even if it is under water?"
"I had a bad feeling", she said.
CNN cited state-run news agency Telam which reported that Balbi said the conditions Wednesday were ideal for the aerial and nautical search.