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 head of the rescue mission, Narongsak Osottanakorn, said last week they would bring the fittest people in the group out first.
When the boys are freed, they will immediately be taken to Chiangrai Prachanukroh hospital, around 60 miles from the cave site.
Additionally, the continuance of the rescue operation is dependent on the weather holding out, with rain potentially causing delays.
Meanwhile rescuers fed a kilometres-long air pipe into the cave to restore oxygen levels in the chamber where the team was sheltering with medics and divers.
He said it's expected to take many hours - and could take days - for all 12 boys and their coach to emerge. Somboon Sompiangjai, 38, the father of one of the trapped boys, said parents were told by rescuers ahead of Sunday's operation the "strongest children" would be brought out first.
"I would like to inform the public at home and those who have been giving us support all along, after 16 days, today's the day we've been waiting for, we are seeing the Wild Boars in the flesh now".
A group of 18 divers - 13 foreign and five Thai - began the operation at 10 a.m. Sunday local time to bring the 13 people out of the Tham Luang Nang Non cave in Chiang Rai province after the area saw mild weather and falling water levels in the cave.
The letters were posted to the Thai Navy SEALS Facebook page.
According to the Associated Press, Thai officials said the healthiest boys have been taken out of the cave first.
The boys urged relatives "not to worry" and asked for their favourite food once they were safely evacuated, in notes handed to divers.
This technology is being developed as 4 boys were rescued with the hopes to see the others safe soon.
Thailand's Meteorological Department said there was a 60 per cent chance of rain with more thunderstorms forecast throughout the week.
Officials wouldn't say how much diving the boys would be required to do in the rescue operation.
Sustained heavy rains could make the water rise to the shelf where the children are sitting, reducing the area to less than 108 square feet, he added, citing estimates from cave divers and experts.
Global rescue teams from the U.S., China, Australia and Europe are stationed along tunnel walls from the entrance of the cave to chamber 3, a safe command center inside the cave, to support the extraction.
Their teammates remain trapped in the caves with their coach, with the operation resuming today.
Footage shared on Musk's Twitter account shows a group testing the device in a Los Angeles high school swimming pool.
"I confirmed the factors [affecting the mission] are as good as yesterday".