"From the outset, it would have been a very fortunate thing if anyone has survived the first explosion, and the circumstances of a coal mine post an explosion make the chances of survival very difficult," Mr Broad told waiting media as he and police minister Judith Collins arrived at the Greymouth Airport just after 1.30pm.
The pair will travel straight to a briefing with the officer in charge of the rescue, Tasman police district commander Superintendant Gary Knowles, before visiting the mine and attending further briefings later in the day.
Asked if body identification teams were on standby in Greymouth, he said police had "all sorts of capability" ready to go.
Four days after the Pike River coal mine explosion, hopes of a successful rescue are slowly dwindling as the realisation grows it could take weeks to enter the mine.
Families of the 29 missing miners were briefed early this morning on the painfully slow process.
Hopes were lifted a little yesterday when it was announced a robot would enter the mine as drilling a new hole continued with the aim of lowering in a camera and listening device to provide an accurate indication of conditions underground.
But some of those hopes were dashed when the army's robot broke down after going only 550m. The drilling of a bore hole continues, with the hope it will be completed this afternoon.
Reverend Tim Mora was at the meeting with family this morning. A popular and approachable member of the local clergy, he is close with many of them and officiated at the weddings of two of the 29 miners.
The main question families were asking mine officials was: "How far into the future will it be before you can go into the mine?"
He told NZPA people were hoping a whole lot of things had come together to keep their men alive.
"(But) there is a realisation now. There is the possibility that they are not going to come out of there. If it is going to take two or three weeks, then that will be far too late."
The man co-ordinating the rescuers says it is "heart-wrenching" not being able to get in and rescue their mates.
New Zealand Mines Rescue general manager Trevor Watts told a press conference 65 rescuers and 30 logistical support personnel were ready to go in and rescue the 29 miners trapped since an explosion on Friday afternoon. Nothing has been heard from them since.
"We have got highly trained and experienced mines rescue personnel waiting to go and collectively, between ourselves, the police, the mine management, we are unable to do so on the back of expert analysis around explosibility of gases," he said.
"All our operational plans and risk assessment processes are completed and all our teams are being briefed as they rotate through a 24-hour period on those operational plans.
"Everything is ready to go.
"I can't express the frustration that our guys feel at not being able to deploy underground. It is heart-wrenching."
Police superintendent Gary Knowles acknowledged for the first time yesterday that there was a possibility of deaths as a result of what had happened.
"The longer this goes on then hopes fade and we have to be realistic," he told media today.
The men underground had little food with them. It is not clear if they have access to drinking water or fresh air or what injuries they may have sustained in the blast.
Pike River chief executive Peter Whittall said the men had a self-rescuer with them, which could provide a small amount of oxygen, a lamp that could last 24 hours, protective gears and safety goggles. They would have had their lunches in preparation for their shift.
Mr Mora said the confusion around technical aspects of the mine had confused many of the family members and extra experts would be brought to this afternoon's meeting to help explain.
"The confusion that people have felt makes things worse and the more you know the better it is."
A triage centre will be set up at the Salvation Army centre in Greymouth today for the families of those trapped underground and each family unit has had access to a counsellor over the last few days.
