"The divers will work with the medical team inside the cave to determine who should be brought out first". Osatanakorn said the rescue, which began at 10 a.m. Sunday local time, has been going better than expected.
On Sunday morning, Governor Narongsak Osottanakorn said a team of 13 global divers and five Thai Navy SEALs went into the cave to commence the mission. "We can not wait any longer".
"They insist they are ready to come out", Narongsak said Sunday of the rescue team.
Signs that a rescue operation was under way were evident in the hours leading up to the announcement, as authorities installed a large green tarp around the cave entrance and removed media from outside of the camp to a separate location.
The Guardian are reporting that the water levels have dropped significantly since Saturday and that officials have not commented on whether the boys will need to dive out of the caves, but they have confirmed that the water levels have dropped enough that the majority of the cave system was now walkable.
The boys emerged several hours after a team of 13 worldwide cave diving experts and five Thai Navy SEALs entered the cave to begin the treacherous attempt to accompany the boys one by one through the flooded, narrow tunnels.
The 25-year-old soccer coach has written as well, thanking people for support and apologizing to the parents of the boys.More news: Daniel Cormier claims UFC heavyweight championship with KO of Stipe Miocic
"We have two obstacles: water and time. The boys are ready to face any challenges", rescue chief Narongsak Osottanakorn told reporters near the cave site as weather forecasters warned of more monsoon rains late on Sunday that would cause further flooding in the cave.
The boys were found inside the cave by British rescue divers on Monday, about 4km (2.5 miles) from the cave mouth.
Shortly after it was reported that two boys have been evacuated, an ambulance believed to be transporting the boys was seen leaving the area.
Narongsak offered condolences to the family of Saman Gunan, the former Thai navy diver who died Friday after placing spare air tanks in a flooded passageway.
More than 100 exploratory holes were also bored - some shallow, but the longest 400 metres deep - into the mountainside in an attempt to open a second evacuation route and avoid forcing the boys into the unsafe dive. The rescue was abandoned for the day, just after 8pm local (1am NZT). "Based on the complexity and difficulty of the cave environment it is unknown how long it might take and how many children would exit the cave".
Given the risk of the oncoming rains that could undo the drainage efforts, Mr Narongsak said the conditions were now ripe for the boys to be evacuated.
He added doctors assessed they were "very fit physically and mentally".More news: Concerned England fans make the same joke about the referee against Sweden
However another operation commander said the operation would take two to 3 days to complete, with the boys and their coach being brought out one-by-one, and that the weather conditions would play a role in determining how long it would take.
The four boys rescued Sunday have been taken to a hospital.
According to rescue officials, he is among the weakest in the group, in part because he gave the boys his share of the limited food and water they had with them in the early days. The first group will have four people, while the second, third and fourth will have three people. Mental health effects could include depression, anxiety, anger and an inability to adjust to normal sleep patterns, said Jacob Hyde, an assistant professor of military psychology at the University of Denver who studies reactions to isolated, confined environments.
Crews on the mountain have drilled more than 100 holes - one of them 400 meters deep - but none has reached the cavern where the group is trapped.
"Cultural factors have and will continue to come into play here", Hyde said. As the world waits for their escape, the boys have written letters to their parents.
On Saturday, Thai Navy SEALS published touching notes scrawled by the trapped footballers to their families, who had been waiting for them agonizingly close by outside the cave entrance.
Thai rescuers are being assisted by an global team comprising experts from China, Australia, the United States and Britain.More news: United States jobs growth stronger than expected
"Hooyah", the post said in English.