Australia warmed up for the tournament with victory in last month's Netherlands triangular tournament and also edged out Pakistan in a one-off game at Lord's on Saturday.
Shane Warne has retired from the one-day game but 34-year-old Glenn McGrath should spearhead the attack in what could be his last one-day tournament.
Andrew Symonds particularly impressed with bat and ball in the warm ups, hitting 104 on Saturday and taking some crucial wickets.
"We had a short break soon after arriving in the UK, and since then have had some good quality practice so the boys are feeling fresh leading into the month ahead," captain Ricky Ponting said.
New Zealand are not a team packed with stars but are one of the best units in the competition. Stephen Fleming is an articulate leader who can alter his batting style if the situation demands.
They cantered to victory in the triangular series in England in July and are used to the pitches, with medium pacer Scott Styris being surprisingly effective.
Qualifiers the United States will rely on former West Indies Test and one-day batsman Clayton Lambert, 42, alongside various other expatriates.
All rounder Tony Reid, also 42, had trouble reaching England when a hurricane delayed his departure from Florida but after the trouncing they are expected to receive he might wonder why he bothered.
Group A Fixtures:
September 10 - New Zealand v USA, The Oval
September 13 - Australia v USA, Rose Bowl
September 16 - Australia v New Zealand, The Oval
