Thai authorities say they are committed to "100 per cent safety" when they consider how to extract a youth football team from the partially flooded cave where they were found after a desperate search.
Chiang Rai Governor Narongsak Osatanakorn said a Navy Seal team will make the final call on the evacuation method from the cave complex in northern Thailand.
He said one way being considered is for the group to be coached to swim out of the complex using special breathing masks.
Other solutions would be considered, such as draining water from the cave and exploring the mountainside for shafts and other entrances to the caverns below.
Experts have said the safest option could be to supply the 12 boys and their coach where they are and wait for the water levels to drop.
Thailand's rainy season typically lasts through to October.
The boys, aged 11 to 16, and their 25-year-old coach were found late on Monday night during a desperate search that drew international help and captivated the nation.
Video released yesterday by the Thai Navy showed the boys in their football uniforms sitting on a dry area inside the cave above the water as a spotlight, apparently from a rescuer, illuminated their faces.
In the tape of the encounter, one of the British rescuers asks, in English, how many were in the group.
Thirteen, the boys report. "Thirteen, brilliant!" the diver replies - the number accounts for the entire missing party.
They went into the cave after practice on June 23 and became trapped by rising water.
Osatanakorn said members of the group have all had an "informal" medical evaluation inside the cave and most were in stable condition.
A field assessment in which red is critical condition, yellow serious and green stable condition was used.
"We found that most of the boys are in green condition. Maybe some of the boys have injuries or light injuries and would be categorised as yellow condition. But no one is in red condition," Osatanakorn said.
Family members of the missing youths hugged each other and cheered as they heard they had been found.
Divers found the group about 300m to 400m past a section of the cave on higher ground that was thought to be where they might have taken shelter. Rescuers reached the group after enlarging a narrow, submerged passageway that had been too small for them to get through while wearing air tanks.
Huge pumps were used to reduce water levels, and divers placed guide ropes and air tanks along the route to reach the trapped boys.
In the five-minute Navy video, the boys are quiet as they sit on their haunches, legs bent in front of them.
"You are very strong," one of the rescuers says in English. Someone asks what day it is, and the rescuer responds, "Monday. Monday. You have been here - 10 days."
One boy, noticing the camera and hearing unfamiliar words, says in Thai, "Oh, they want to take a picture; tell him we're hungry. I haven't had anything to eat."
Then the boy breaks into simple English, saying, "Eat, eat, eat," to which another voice responds in Thai that he already told the rescuer that.
The group was given high-protein liquid food, painkillers and antibiotics.
Osatanakorn said doctors had advised giving the medicine as a preventative measure.
An American cave rescue expert, Anmar Mirza, said the primary decision was now one of whether to try to evacuate the young footballers or to supply them in place.
Mirza, the United States National Cave Rescue Commission coordinator, said: "Supplying them on site may face challenges depending on how difficult the dives are.
"Trying to take non-divers through a cave is one of the most dangerous situations possible, even if the dives are relatively easy."
Thailand's Prime Minister has thanked international experts and rescuers who helped find the group.
Prayuth Chan-ocha said he "wishes to thank the tremendous efforts of all international units that have come to assist the Thai authorities in rescuing the youth football team that was stuck in the caves in Chiang Rai.
"The Royal Thai Government and the Thai people are grateful for this support and co-operation, and we all wish the team a safe and speedy recovery."
The stunning news that the teenage Thai football team had been found alive deep inside a flooded cave was greeted with relief and elation outside the entrance and across the country.
Near the cave portal at Chiang Rai, a woman clutched an iPad showing pictures of some of the boys, with relief and joy spreading over her face as news of the discovery emerged.
A parent shared the joy: "I'm so glad ... I want him to be physically and mentally fit," said Tinnakorn Boonpiem, whose 12-year-old son Mongkol is among the rescued group.
"I found out from the television ... I'm so happy I can't put it into words," another relative of one of the footballers told television reporters with tears of joy streaming down his cheeks.
As the news broke, there was an explosion of shouts and cries of relief in the makeshift rescue camp set up near the cave entrance. Family members broke down as they looked at the grainy black and white images of their children taken by cave divers.
Elated workers exchanged high fives and slapped each others' backs as it emerged that British divers had made contact with the boys deep within the cave complex.
"Today is the best day," one mother said, waiting outside the cave in darkness. "I have been waiting for my son for so many days, I thought he had a 50 per cent chance of survival."
Other mothers said they were already planning welcome home meals to cook for their children; a Thai fried omelette for one, fried rice for another.
Reuters correspondent Panu Wongcha-um told CBC news the "huge story" had gripped the world.
"It is really a time when the entire nation has come together, to give their support, to share their concern, and at the same time there were moments of anxiety and even despair," said Wongcha-um.
"All that changed overnight. They [the families] were crying with joy, not only the relatives but people around them; officials, rescuers, and journalists.
"I mean this hasn't been the most easy story to cover ... but all this has changed now, and we hope that the next phase of the rescue operation will be successful."
Adisak Wongsukjan's 14-year-old son Ekarat is one of the 12 young football players trapped in the cave. He told CNN he was happy to hear the cheering from the rescuers and is hopeful he will see his son alive.
"I am very happy, I am very proud. Even if it was the soldiers, the police and rescue team. Thank you to everyone for helping get all 13 of them out," he said. "I want to hug my son."
Authorities said they're trying to bring phone lines inside the cave so that the boys can speak with their parents.
In a country that has been deeply divided by political strife and remains under military rule following a coup four years ago, the sight of mud-caked soldiers and volunteers working in pouring rain has filled Thais with both pride and a sense of common cause.
Lamduan Mayula travelled to the cave from Payao province, where she owns a gift shop and also volunteers as a rescue worker.
She and her friends have set up a kitchen and hand out food to hungry workers.
"I just feel like I have to do something. I can't be sitting at home and watching the news," she said.
"And I will stay here until we and the boys and their coach can all go home together."
• Saturday, June 23: Twelve Thai boys, aged 11 to 16, and their 25-year-old football coach went into the Tham Luang cave in northern Thailand after practice. They were reported missing that night.
• June 24: Search starts as heavy rains fall in the area, flooding the underground system.
• June 25: Thai Navy Seal divers with oxygen tanks and food search in the caves. Heavy rains continue.
• June 26: Divers reach a T-junction three kilometres inside the cave but are forced back by rushing floodwaters that clog a narrow crevice near Pattaya Beach.
• June 27: An American military team and three UK rescue and survival specialists arrive.
• June 28: Rising floodwaters halt the rescue. Water pumps delivered and drones search the terrain.
• June 29: Rescue teams find a possible opening. Thailand's junta leader, Prayut Chan-o-cha, visits and urges families to remain hopeful.
• June 30: Break in weather allows divers to move further into system.
• July 1: Rescuers set up base in the cave and move oxygen tanks inside.
• July 2: The boys and their coach are found alive and safe about 400m along from Pattaya Beach. A nation is relieved.
- Agencies
Homeland Security says Brad Lander was arrested for assaulting and impeding officers.