Typhoon Hagibis also forced World Cup organisers to cancel England's pool game against France and they may yet have to do likewise for Japan's final group game with Scotland which will determine who the All Blacks face in their quarter-final.
"Everyone knew this was a possibility and we all knew what the process would be if it did occur," Hansen said in Tokyo today. "When you get a typhoon to the level we're getting then safety is the paramount thing so it's a no-brainer. A man from America could have even made this decision.
"These guys have about 25 typhoons a year and a heck of a lot of earthquakes so in our planning we had to take that into consideration. Did we think we'd get a game cancelled? No but that's out of our control.
"Now it's happened we adapt and adjust. That's what we do on the park and you've got to do it off the park sometimes."
As they move swiftly to alter plans, Hansen hinted the All Blacks may now stage an inter-squad training match this weekend in an attempt to simulate scenarios and contact they would otherwise have received from Italy on Saturday.
After two comfortable victories over Canada and Namibia, followed by a two-week break without a game, there will now be fears the All Blacks could be somewhat undercooked for next week's quarter-final.
"What we do will be behind closed doors so there's no point telling everyone else because then they might copy it. Obviously we're going to have to replicate something that was going to happen on Saturday so it'll be a decent training run.
"We've got 31 fit people so if we want we can have a game against ourselves.
"Apart from Brodie Retallick and Jack Goodhue, who probably need a bit of footy, it's not a disruptive thing at all. We're choosing to look at it as a positive. It now gives us more time to plan against whomever it is it we get in the quarter-final and we just have to modify our training run."
Hansen said the All Blacks considered the possibility of staging their game against Italy one day earlier to avoid the typhoon but tournament rules were clear about not moving pool matches.
"We talked amongst ourselves about those sorts of things but it's not our decision to make. They didn't come and ask us.
"The logical thing for us is, if we had a choice, was to play Friday. It's going to be 28 degrees and no rain. But it's out of our control.
"At the end of the day we've got to back World Rugby for the decision. If other teams miss out having the opportunity to get into the knockouts it will be disappointing.
"If you want to be really ruthless it's about making sure you win the games on the way through because everyone knew this would be a possibility but that's pretty hard-nosed.
"I know if we were in their situation we'd be disappointed not to have the opportunity to get there."
In the wake of this havoc, World Rugby have been criticised for staging the tournament in Japan during typhoon season.
Asked whether the global showpiece should have been held at a different time, Hansen said: "This has been a marvellous tournament and hopefully it's not remembered because of this. There's been some wonderful rugby played and some great support.
"This is when we play the Rugby World Cup. If you play it earlier you run the risk of people dying on the footy field because it will be 40 degrees. If you play it later then we'll finish at Christmas and you'll end up Santa Claus giving us the World Cup.
"It's really the only time we can play it. It's frustrating but the reality is we can't control the weather."