New Zealand Sevens Coach Gordon Tietjens believes the 2010 IRB Sevens Series will be a close contest between his side, Fiji, Samoa and England.

Tietjens said his side cannot afford to lose in the early stages of the USA 7s this weekend, as they are just four points ahead of Fiji are the favourites for Las Vegas.

He added they will work on their defence after Samoa scored three second half tries to stun New Zealand 24-14 in the cup semifinals, before losing the finals to Fiji.

Tietjens will fly out with the same 12 players today and is sure to ram home the need for greater commitment than shown in the 24-14 semifinal loss to Samoa.

Lax defence and hesitancy in competing for the ball was fully exploited by the Samoans, who thrive on sensing another team aren't up for the fight.

New Zealand who still lead the points standing with 64 points are pooled with France, Guyana and Australia in USA.

The USA Sevens kicks off on Saturday night with Fiji's opening pool game against USA at 8.44pm.