The U.S. Navy has deployed unmanned underwater vehicles (UUV) to join in the search for the Argentine navy's submarine, A.R.A. San Juan, in South Atlantic waters.
Seven failed satellite calls were intercepted by Argentina's defence ministry on Sunday, raising hopes the sub and the 44 people on board would be found.
USA satellite communications company Iridium Communications Inc, which was brought in to help analyse the calls, said they did not originate with its device aboard the vessel and may have been from another satellite communications company's equipment.
An Argentine national flag hangs at the entrance of the Argentine Naval Base Mar del Plata, where the missing submarine is based.
Argentine Pope Francis mentioned the vessel in his Sunday prayer.
Three boats left Mar del Plata on Saturday with radar detection probes and were following the path that the submarine would have taken to arrive at the base in reverse, Balbi said.
On Saturday, the Undersea Rescue Comand, or URC, shipped out two "independent rescue assets" from San Diego en route to the Southern Atlantic, where the Argentine Navy lost communications with one of its submarines.
Helping to search for the ARA San Juan are Chile, Brazil, the USA, the United Kingdom, Colombia, Uruguay and Peru, although other countries have offered their cooperation in the search and rescue operation, Argentine Defence Minister Oscar Aguad confirmed on Saturday, Efe news reported.
The systems allow the safe underwater transfer of sailors from a submarine at a depth up to 850 feet.
The German-built diesel-powered vessel set sail on Monday from the southern port of Ushuaia enroute to its base in Mar del Plata, farther north in Buenos Aires province. However, it would not be unusual for storms to cause delays, Balbi said.
He said: "I pray for the men of the crew of the Argentine military submarine which is missing".
U.S. Southern Command (SOUTHCOM) directed the deployment of this equipment and personnel to Argentina to support the country's request for worldwide assistance aimed at locating the missing submarine and crew.
By Sunday, the pursuit to pinpoint the pings will be bolstered by the might of the U.S. Navy and Air Force, which are deploying more resources into the massive rescue mission already underway to locate the missing submarine, Pentagon officials told ABC News.