Rescuers are on standby to enter the Pike River coal mine to bring out their brothers, and will go in at the slightest opportunity.
But police and rescue co-ordinators first want to ensure the mine is safe for the team to enter.
Trevor Watts, general manager of New Zealand Mines Rescue, said the rescue would be a staged event.
"The safety of our personnel is paramount as well as that of the trapped miners," Mr Watts said.
"We need to secure areas in the mine as we go. We're still in the gun barrel," meaning that the mine tunnel remains potentially explosive.
"At the moment, we are in rescue mode," Mr Watts said in response to a suggestion that the miners may have come to harm.
"The analysis we have at the moment suggests that something else is occurring, but there's limited information.
"It's still in the gun barrel. They are still in part of the mine. They are still in direct travel of an explosion path."
When the rescuers went into the mine, they would have to walk, Mr Watts said.
"This is not an easy task. It's not like walking down to the local supermarket. The floor conditions are uneven. We can't just throw face masks on people and put them into the mine in a hurry.
"The logistics of deployment underground are quite vast.
"We're talking two and a half kilometres from the portal to the first intersection in the mine that will have to be done on foot."
It was an uphill walk, he said, and the rescuers would each be fitted with breathing apparatus weighing about 14kg. They would also have 5-10kg of other equipment.
The walk in could take "anything up to two hours".
Mr Watts said they would not be wearing specialist clothing, just their regular overalls. And they would have to work their way around the loader one of the survivors, Daniel Rockhouse, was driving at the time of the explosion.
The initial team of rescuers into the mine would have to withdraw after reaching the first intersection.
"[That's] because of the timeframe, and return to a fresh-air base that we'll have established on the surface."
Mr Watts said plans were in place to get out any of the trapped men found along the way, but he would not disclose what they were..
"We've got a number of factors to work around. We're suitably equipped to deal with any event over the coming days. If we get that window of opportunity, we will deploy."
The rescuers are ready to go in the second the opportunity arises.
They are working in shifts and may be joined by a seven-man team from New South Wales Mines Rescue, who are in Christchurch ready to travel to Greymouth if needed.
"The whole lot of them are our brothers and we know all of these guys there and if there is the slightest opportunity to go underground then we will be going," Mr Watts said.
The Tasman District police area commander, Superintendent Gary Knowles, said he was not prepared to put rescue teams underground while there was any risk to their safety.