TOKYO -- Indonesia has ramped up its search for a missing submarine, as concerns over oxygen supply on board the vessel continue to mount.
Indonesia increased the numbers search vessels to 21 on Friday from five a day earlier to look for the KRI Nanggala 402 which went missing in the early hours of Wednesday with 53 crew on board. One newly deployed vessel is a submarine.
Various countries have offered help, with two ships from Australia, and one each from Singapore, Malaysia, India and the U.S. set to join the mission. The ship from Singapore is set to arrive later Friday, Indonesian military spokesperson Achmad Riad said at a news conference.
Air on board the submarine is set to last for 72 hours, giving search and rescue teams until early Saturday morning to find the vessel.
The U.S. will "do everything possible to support Indonesia's search and rescue effort," National Security Adviser Jake Sullivan told Foreign Minister Retno Marsudi in a phone call, according to U.S. National Security Council spokesperson Emily Horne. The minister confirmed on Twitter that she had had a "good phone conversation" with Sullivan.
U.S. Secretary of Defense Lloyd Austin called Indonesian counterpart Prabowo Subianto "to express his heartfelt concern" over the missing sub and its crew. The two defense chiefs discussed the deployment of a P-8 Poseidon aircraft to aid in the search, as well as the possibility of additional support, including "underwater assets," according to Pentagon press secretary John Kirby.
Contact was lost with KRI Nanggala while it was preparing for a torpedo-firing exercise in the early morning of Wednesday in waters north of Bali.
"The search is focused on the location where a strong magnetic reaction is found," Riad said, referring to the finding on Thursday of an object with a high magnetic force at a depth of 50-100 meters. "Hopefully this will not change, and it will be pursued. But all of the waters north of Bali will continue to be combed using existing equipment and ships."
The German-build submarine has been in service since 1981, and had undergone a full refit in South Korea that was completed in 2012. The Indonesian navy said it was "in good condition."
In an online address yesterday, President Joko Widodo said the "top priority is the safety of 53 crew members."
"To the family of the crew members, I understand very well the feelings at this time and the government will do its best to search and rescue the crew," he said. "I would like the public to pray for this search and rescue to be carried out."