Narongsak Osottanakorn, the governor of the country's Chiang Rai Province and the leader of the rescue mission, said the dive team is working with doctors to determine the order of exit, per Forgan.
The rescue operation is due to resume at 8am on Monday.
The dozen boys between the ages of 11 and 16 are accompanied by their 25-year-old coach.
Chiang Rai Gov. Narongsak Osotthanakorn said at a press conference four boys are safely in the hands of doctors.
"We're ready for the operation today", said Narongsak, who said the weather and the water levels in the cave are good.
More than 90 divers took part in the rescue operation on Sunday, which kicked off at 10am (local time).
Mirza is the national coordinator of the National Cave Rescue Mission. They had been missing for 10 days before they were discovered.
Billionaire entrepreneur Elon Musk tweeted that a team from his rocket company SpaceX in Los Angeles is building a mini-sub to help with the rescue.
Picture of ex-Thai Navy diver Saman Gunan, who died during early rescue efforts at the Tham Luang cave.
Further adding to speculation that the weakest were rescued first was the condition of the first boy taken from the cave. Several ambulances were seen coming to and from the cavesite.
The area outside the hospital was cordoned off with police patrolling the area.
His parents, who along with other families, have maintained a constant vigil at the site since the boys first became trapped.
Two of them have been taken by ambulance to hospital while another two were airlifted, but none of them were stretchered out.
The Thai government released a graphic showing how the rescue from the Tham Luang cave would occur. Experienced cave rescue experts consider an underwater escape a last resort, especially with people untrained in diving, as the boys are.
The Guardian reports that four boys have been rescued from the Thailand cave.
"Now and in the next three or four days, the conditions are ideal (for evacuation) in terms of the water, the weather and the boys' health", Narongsak told reporters.
"Today is D-Day", Mr. Narongsak had earlier told reporters.
An Australian doctor who is part of the global team of rescuers checked the health of the boys Saturday to decide who should be brought to the surface first.
Time is running out on a plan to teach the boys - some as young as 11 and not strong swimmers - to make a dive through dark, narrow passageways sometimes no more than 0.6 of a meter wide, that have challenged some of the world's leading cave divers.
Ever since the remarkable first images emerged of Thai schoolboys huddled alive and relatively well, three kilometres into a cave system, a race has been on to extract them before too much water, or too little oxygen, runs its course.