"It's always humbling when your accomplishments are recognised in a tangible way and this ranking is a sign that we are doing something right in terms of our overall goal, which is simply to continually strive towards achieving our potential," he said.
"We're somewhat fortunate that we've been able to field close to our strongest side over our last two campaigns - the Four Nations and this month's Anzac test. Compare that with last year's Anzac game, when we had about 16 players unavailable."
Kearney added: "But it's also the result of some hard work put in by New Zealand Rugby League over the past 12 months, and a testament to the players and staff that have really bought into that culture of constant improvement.
"Despite this accolade, we still consider Australia as the benchmark for international rugby league and we know that defending this number one ranking against England on their home soil later this year will also present a wonderful challenge for us."
New Zealand will now be aiming to strengthen their hold on top spot in a three test series against Great Britian at the end of the year.
Rankings
1 - New Zedaland
2 - Australia
3 - England
4 - Samoa
5 - France
6 - Fiji
7 - Ireland
8 - Scotland
9 - Wales
10 -USA
