BUENOS AIRES, Argentina (AP) — Bad weather has delayed the arrival of a U.S. undersea rescue module at an area in the South Atlantic where an Argentine submarine went missing with 44 crew members 13 days ago, the Argentine navy said Tuesday.

A Norwegian ship carrying the U.S. Navy's underwater remotely operated vehicle and its pressurized rescue module was expected to arrive at the search zone later in the day or Wednesday. It had been expected to arrive Monday.

Some families of the crew have lost hope that their loved ones will be rescued following the navy's report that an explosion occurred near the time and place where the ARA San Juan went missing on Nov. 15.

Navy spokesman Enrique Balbi said Tuesday that the blast could have been caused by a "concentration of hydrogen" caused by a problem reported by the captain: a short circuit when water entered the vessel's snorkel. The captain, however, later communicated by satellite phone that the problem had been contained and he would continue sailing from the extreme southern port of Ushuaia to the sub's base in the coastal city of Mar del Plata, some 230 miles (400 kilometers) southeast of Buenos Aires.

Experts say that even if the vessel remained intact under water, the crew only had enough oxygen to last up to 10 days.

More than a dozen countries are still searching for the TR-1700 class submarine that was commissioned in the 1980s and was refitted in 2014.Efforts by ships equipped with sonar have focused on an area of about 1,500 square miles (4,000 square kilometers).

"There's no date for the end of this international help," Balbi said.

"This is a critical situation, of high anxiety and concern for the family members of the crew and everyone in the navy who has been on this search for 13 days."