One of three shafts being drilled down to the 33 men trapped in a mine in Chile should reach them by Saturday, the country's mining minister has said.
Laurence Golborne said the T-130 drill, known as "plan B", had already carved through 535m (1,755ft) of rock and had only 90m to go.
Once complete, engineers will assess how safe the shaft is before they can begin winching the men to the surface.
Mr Golborne said the miners should have to wait 10 days at most to be rescued.
"We expect to break through around Saturday," Mr Golborne told reporters, but warned the process could be slower if any of the drilling equipment needed to be changed.
The operation was briefly stopped on Wednesday so the drill hammer could be replaced.
Mr Golborne said the operation to winch the men out could not begin as soon as the shaft was complete.
Engineers would first need to assess whether it had to be coated with metal or was secure enough by itself for rescue capsules to be lowered down.
Health Minister Jaime Manalich called on the Chilean public to be patient while the complex process was carried out.
"All the drilling gear on top has to be removed, cranes installed, and the final rescue equipment has to be set up," the AFP news agency quoted him as saying.
"At least three or four more days will be needed, not counting the probable need of reinforcing all or part of the tunnel."
Mr Manalich also praised the "maturity and manhood" of the miners.
"They are more relaxed and in control of the situation than we are on the surface," he said.
The men were trapped by a rockfall at the mine on 5 August.
Rescuers had almost given up hope of finding the men alive until they made contact with the miners 17 days after the accident and found they had sought refuge in a shelter some 700m underground.
The miners have now been underground longer than any group before.
When the time comes for them to be hauled out, rescue workers will go down into the mine to help them use the rescue capsules.
It is expected to take at least an hour to pull each of the trapped men to the surface - they will each be given sunglasses to protect them from the light, after spending two months with no natural light.