BUENOS AIRES, Nov. 24 (Xinhua) -- Argentinean President Mauricio Macri ordered on Friday a "serious investigation" into the circumstances of the missing submarine ARA San Juan, which vanished on Nov. 15 in the South Atlantic with 44 crew on board.

The president spoke to the press from the Argentinean navy headquarters in Buenos Aires, saying that "This is a difficult moment for all, especially for the families of the 44 crewmembers."

Macri said the situation would "require a serious, deep investigation, which brings certainty...to how a submarine which had had its half-life reparation and was in condition to sail, apparently suffered this explosion."

The president was referring to the overhaul of the submarine that took place between December 2008 and June 2014.

During his speech, Macri said "for the next days...to see the highest respect given for the pain this has caused, especially to the families."

However, he promised that the search would continue, with the vast amount of international support Argentina has received. "We will make every effort to find the submarine in the coming days."

"While we do not have the complete information, we will not risk seeking to find the guilty, to find those responsible," added Macri. "First, we must have certainty about what happened and why it happened. My commitment is to the truth. We will learn the truth in time through this investigation."

He also extended his gratitude to the 44 crew for "their patriotism, their heroism, their bravery...as they have a central responsibility in the life of this country: to take care of our territory...and of us all."

On Thursday, the Navy reported that on the day the submarine disappeared, an event "consistent with an explosion" was registered in the area the submarine was travelling in.

The ARA San Juan's last-known position was in the San Jorge Gulf, 240 nautical miles southeast of the Valdes Peninsula.