The Argentine navy can be stepping up its search inside the South Atlantic for a 44-crew submarine which has been out of radio contact for three days.
President Mauricio Macri said all national in addition to international resources were being deployed to help find the San Juan as quickly as possible.
A Nasa research plane has joined the search for the vessel.
Britain in addition to countries inside the region have offered help after the item disappeared 430km (267 miles) off the coast.
“We have not been able to find, or have visual or radar communication with the submarine,” navy spokesman Enrique Balbi told a news conference.
The diesel-electric submarine was returning via a routine mission to Ushuaia, near the southern-most tip of South America, to its base at Mar del Plata, south of Buenos Aires.
Its last contact with the navy command was on Wednesday morning.
An Argentine destroyer in addition to two corvettes are conducting a search around the area of the sub’s last known position off the south-eastern Valdez peninsula.
nevertheless so far there are no clues about its whereabouts.
The rescue operation has been formally upgraded to a search-in addition to-rescue procedure after no visual or radar contact was made with the submarine, Mr Balbi said.
“Detection has been difficult despite the quantity of boats in addition to aircraft involved inside the search”, he said.
The task of the rescuers has been further complicated by heavy winds in addition to high waves.
Mr Balbi said which the number of hours which had passed since there had been any communication with the vessel was of concern.
the item can be thought which the submarine may have had communication difficulties caused by a power cut.
Navy protocol dictates which a vessel should come to the surface if communication has been lost.
“We expect which the item can be on the surface,” Mr Balbi said.
The German-built submarine was inaugurated in 1983, the newest of the three submarines inside the Argentine navy’s fleet.
President Macri said the government was in regular contact with the crew’s families.
“We share their concern in addition to which of all Argentines,” he wrote on Twitter. “We are committed to using all national in addition to international resources necessary to find the ARA San Juan submarine as soon as possible.”
A US Nasa P-3 explorer aircraft – capable of long-duration flights – can be preparing to take part inside the search, Mr Balbi said, in addition to a Hercules C-130 via the Argentine Air Force.
Brazil, Chile, Uruguay, Peru, in addition to South Africa have all formally offered assistance inside the search.