APIA, Samoa (AFP) - Samoa is expected to come to a standstill on Wednesday, when the All Blacks launch their World Cup preparations by playing in the rugby-obsessed island nation for the first time.

Samoan Prime Minister Tuilaepa Sa'lele Malielegaoi has declared a half-day holiday to mark the historic occasion with a raft of public activities including a street parade for the All Blacks.

"We have to have a half day. It's a day where everyone should prepare to support the boys," he told the nation of 192,000.

World Rugby hall-of-famer Michael Jones, who represented both countries in his stellar career, said the long-awaited match was "huge" for Samoans.

"It's certainly something that's going to bring the whole country and the hundreds of thousands of Samoans around the world to a standstill," he said.

The significance of the festival atmosphere was not lost on All Blacks coach Steve Hansen but he warned his world champion side not to be overawed.

"Clearly it's going to be a big occasion and it will be good for our guys to have to do something a bit different and see how they react, including myself."

However, his prime focus is to achieve a successful start to his goal of having the All Blacks become the first team to win back-to-back World Cups.

"If we don't take them seriously we will get one right between the eyes because they are a good side."

Samoa is the first of five Tests the All Blacks have before Hansen settles on a 31-man squad to defend their world championship.

He started with a squad of 41 and added another nine to compensate for injuries and the unavailability of 17 players involved in Saturday's Super rugby final between the Otago Highlanders and Wellington Hurricanes.

Of the late additions, right-wing George Moala will make his international debut while scrum-half Andy Ellis lines up for his first Test since the All Blacks beat France 8-7 in the 2011 World Cup final.

The same vastly experienced pack led by Richie McCaw who started that final four years ago will take the field against Samoa with the exception of the now retired Brad Thorn whose place is taken by 17-Test lock Luke Romano.

The backline is more makeshift with Dan Carter partnering Ellis in the halves, Sonny Bill Williams and Ryan Crotty in the centres, and Israel Dagg handed the full-back slot despite missing all Super rugby since April because of injury.

"The team picked itself pretty easily. We went for people we want to see and people that need game time," Hansen said.

Samoan coach Stephen Betham has also gone for experience, drawing on 18 European-based players in his 23-man squad and recalling 47-Test veteran prop Census Johnston from retirement.

The only Samoan newcomer is New Zealand-born Tim Nanai-Williams, a cousin of Sonny Bill Williams, who plays Super rugby for the Waikato Chiefs and believes the All Blacks could be vulnerable.

"The pressure is on them because they are the best in the world," he told the Samoa Observer. "As a group we believe we can win. The boys are really up for it."

Conditions will favour Samoa with temperatures around 30 deg C and a rock-hard ground.

"I guess on the day you'll see the kind of rugby we're trying to play. Obviously we want to play the Samoan way - physical - and see what happens from there," Sale centre Johnny Leota said.

At a church service for the Samoans on Sunday, parish priest Ilalio Fulu urged the players to be "tough, but not rough", adding: "If God is with us, who can be against us?"