In comments released by the government, Interior Minister Anupong Paojinda said the same divers who took part in Sunday's rescue will also conduct the next operation as they know the cave conditions and what to do.
The boys and soccer coach trapped in a Thai cave have written a letter saying they're OK.
Aged between 11 and 17, they belong to a football club called the Wild Boars, and became trapped during an excursion with their coach.
The rescue operation began Sunday and has been progressing rapidly.
Narongsak Osottanakorn, head of the rescue operation, said a team of divers went back into the cave Monday morning, local time. Thai Prime Minister Prayut Chan-ocha was scheduled to make a second visit to the scene late on Monday and the president of soccer's governing body, FIFA, Gianni Infantino, today invited the boys to the World Cup final in Moscow on Sunday if they make it out of the cave in time.
Narongsak said that there was no time limit on the rescue and that its progress would depend on weather and conditions inside the cave, but expected it to last through Monday.
Rescuers are moving ahead quickly because they are afraid monsoon rains will completely flood the caves.
The perilous rescues have involved two divers accompanying each of the boys, all of whom have been learning to dive only since July 2, when searchers found them.
Musk also said that a second sub, which is apparently 30cm shorter than the first one designed, was nearly complete, meaning that more than one device would be available for the rescues.
Workers have been laboring around the clock to pump water out of the cave, and officials said Monday that despite heavy downpours overnight, water levels inside the cave did not rise.
Thai authorities sent Harris into the Tham Luang cave to swim to the trapped boys immediately upon his arrival at the site on Saturday.
A total of four ambulances have left the area around the flooded cave in northern Thailand where members of a youth soccer team have been trapped for more than two weeks, suggesting eight of the 13 trapped people have now been extracted.
The experts say if the boys are not rescued over the next few days, they may have to wait inside the cave for months before the rains ease up and another rescue attempt is made.
On July 6th, former Thai Navy diver, Petty Officer Saman Gunan died while helping deliver oxygen to the team. Relatives were able to see them through a glass partition, the governor said. Dr. Paul Auerbach, a professor of emergency medicine at Stanford University School of Medicine, told ABC News that it could take several days for doctors to replenish the nutrients the boys lost during their cave ordeal.
Musk has been tweeting about the rescue effort for days and said he is "amazed by the bravery, resilience & tenacity of kids & diving team in Thailand". On Tuesday we'll all hold our breath once more, in the hope of seeing them emerge.
As an worldwide coalition of divers continued to rescue a Thai soccer team and their coach from a cave Monday, Tesla CEO Elon Musk was trying to help in his own inimitable way. They are then taken to hospital in Chiang Rai.
"I beg Phra Pirun because the Meteorological Department said that from Monday on there will be continuous rain", Major General Bancha Duriyapan said.