Argentina steps up search for missing submarine

BUENOS AIRES, Argentina – Argentina's Navy says it's ramping up the search for a submarine that hasn't been heard from in three days.

Navy spokesman Enrique Balbi said Saturday that the search area off the country's southern coast has been expanded. Six countries are joining in the hunt for the ARA San Juan. They include the United States and Great Britain.

Authorities last had contact with the German-built diesel sub on Wednesday as it was on a voyage from the extreme southern port of Ushuaia to Mar del Plata with 44 crew members aboard.

President Mauricio Macri said in a tweet that the country will use "all resources national and international that are necessary to find the submarine"

From the Vatican, Argentine Pope Francis said he was making "fervent prayers" for the crew.