Hansen congratulated the players named in the squad and offered his commiseration's to those who missed out.
"Over the last couple of months we've spent a lot of time building our game, working on the individual skill sets we want and as selectors, taking the time to get really clear we wanted to put together from a selection point of view, for this team.
"Now we're finally in a position to be able to put all our time, effort and thinking into what's going to be an awesome challenge, doing something that's never been done before and trying to win three world cups in a row. We know it's going to be hard, we know it's going to be tough and we know we're going to have to earn the right to do it," Hansen said.
On Owen Franks omission, Hansen called it a tough decision.
"He's certainly shown true character, his professionalism both on and off the field has been magnificent over the years, he's played over 100 Test matches, but unfortunately we as the three selectors, we believe the game requires us to have big mobile number one and number threes and in this case we just think the other guys are more so than he."
Hansen said Franks was naturally disappointed when he called him to tell him he hadn't made the squad.
Also missing from the squad is Liam Squire, who reportedly called Hansen earlier in the week to make himself available for the world cup.
"We had a phone call," Hansen admitted.
"[It] was a really good phone call actually and discussed things and whilst Liam is playing really well for Tasman, is really enjoying his rugby, at the conclusion of the conversation it was agreed that he would make himself available if we required him as a replacement."
Chiefs flanker Luke Jacobson was arguably the biggest surprise inclusion in the squad for the hotly contested No.6 jersey, but Hansen said his selection is justified.
"He's a former under 20's captain so he's got good leadership skills, defensively he's one of the best hitters in the game, he's a good ball carrier and he's just a smart rugby player so we think he's got a big future."
Hansen said the midfield was another tough choice given the form of Ngani Laumape and injury-prone Ryan Crotty.
"It's one of those positions where five doesn't fit four and whoever we left out was going to be disappointed and probably deserved to be in the team.
"In the case of Ryan, he's got a lot of experience of being with the All Blacks, he's in the team leader group, he's a quality player, can play both second five and centre and those little things probably edged him ahead of Ngani."