Officials say 12 boys and their football coach trapped in flooded caves in Thailand will not be rescued overnight.
The boys have now been trapped for nearly two weeks after heavy rain left them stranded in the cave complex.
Teams are racing against time to get the group out before the weather worsens, with fears rain could increase the level of flooding.
Millions of litres of water are being pumped out of the cave as divers work to prepare an exit route, while the boys are being taught how to dive.
Reports suggested rescue attempts could begin tonight, with divers leading the boys through long stretches of underwater passages.
However, local governor Narongsak Osottanakorn explained that the boys "cannot dive at this time".
Thai rescuers prepare to enter the cave where 12 boys and their soccer coach have been trapped since June 23. Picture by: Sakchai Lalit/AP/Press Association Images
He stressed that while they need to find the plan with the minimum danger, they also "can't wait until it rains heavily" - saying they'll need to reassess if that happens.
The dangers of the route involved were highlighted earlier when it was confirmed a former Thai Navy SEAL - Saman Kunan - had died after running out of oxygen supplies.
Meanwhile, other rescue teams are scouring nearby land in an effort to find any shafts into the cave that could make it easier to reach the boys.
Elon Musk - the founder of SpaceX and Tesla - is also sending a team of engineers to Thailand to see if they can offer any assistance in the ongoing rescue efforts.