After a relatively easy passage into the rugby World Cup semi-finals, the All Blacks have been told they must improve this weekend or head back home.

"For us to succeed this weekend we will have to play better than we have up until this point," coaching co-ordinator Robbie Deans told reporters. "There is no way we will succeed playing at the level we have been."

New Zealand, who are now the International Rugby Board's number one ranked side and the tournament favourites, meet champions Australia in the first semi-final on Saturday.

The All Blacks coasted through their opening three pool games, beating Italy (70-7), Canada (68-6), and Tonga (91-7), but were put under pressure by Wales for 30 minutes of their final game before running out 53-37 victors.

They then met a below par South African side in the quarter-finals last Saturday in Melbourne, comfortably accounting for the Springboks 29-9.

While they never seemed threatened, some felt a more ruthless approach would have seen them run up a victory margin similar to the 52-16 thrashing they dished out in Pretoria in this year's Tri-nations.

"What we encounter at the weekend will be far and above what we have encountered to date," Deans said.

"We will have to be alert and accurate defensively and to really use the ball that we get because they are a side that perseveres."

The All Blacks have had the upper hand over the Wallabies this year, winning both Tri-nations games and regaining the Bledisloe Cup, but coach John Mitchell said past form and the Wallabies' lacklustre performances in the tournament are not relevant.

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"That holds no value at all," said Mitchell in reference to the Tri-nations matches, which included a 50-21 victory in Sydney. "The team has moved on since then.

"This is a separate competition. It's a one-off contest and there is an opportunity for both teams."

Mitchell was also not prepared to join the host of media commentators and former players criticising the Wallabies for their progress and style of play so far.

"It's going to take a massive performance. This is Australia. They're playing the World Cup in their own country, they're defending champions and we never take them for granted.

"They have numerous attacking threats than any other opposition that we have faced to date.

"They are very organised and very structured and if we are not precise and accurate in what we do we will get punished."

While the All Blacks management is not prepared to play down the Wallabies, what may be of particular concern is that all four semi-finalists have been waiting until this point to really make their mark.

It is something that may have been revealed by inside centre Elton Flatley before the Wallabies played Ireland in Melbourne on November 1.

"We would have liked to have won the Tri-nations and the Bledisloe Cup, but all that really counts this year is the World Cup," Flatley said before the final pool match against Ireland on November 1.

"The big trophy that we wanted this year is the World Cup. We would have liked to have had them all, but our focus has been the World Cup."