An international survey has found New Zealand's top students are among the best in the world - but more needs to be done to lift achievement for the rest of our children.

According to the survey of nearly half a million 15-year-olds, New Zealanders perform well above the average for OECD countries in reading, maths and science.

Only students in four of the 65 other countries did better in reading and science while students in 10 other countries performed better in maths.

However, the Programme for International Student Assessment survey also found New Zealand has a disproportionate number of lower achievers - a fact that hasn't changed in the nine years since the survey has been running.

Maori and Pasifika students were over-represented at the low end of the scale and overall reading performance hadn't improved since 2000.

Education Minister Anne Tolley said the finding showed New Zealand had "a lot to be proud of".

"This study confirms our top students are amongst the best in the world."

However she added the challenge "was to now work together to address the issues raised in the report such as the disproportionate number of low achievers and lack of improvement in this area.

"All children deserve the chance to reach their potential, so there is an urgent need to lift achievement levels and raise the bar for our young people."

Ms Tolley said the introduction of "National Standards in reading, writing and maths will help identify and provide support for primary and intermediate students and schools needing extra help.

National Standards would also ensure students arrive at secondary school with the basic skills needed to reach at least NCEA Level 2.

"This Government is serious about education. We won't continue to allow up to one in five of our students to be failed by the schooling system. Every single young New Zealander must be given the opportunity to succeed."

Ministry spokeswoman Mary Chamberlain said it was "clear more support needed to be offered to school leaders and teachers to help raise achievements.

"The establishment of Student Achievement Practitioners, National Standards, improved professional development and more targeted programmes for students were all focused on providing this support."

Ms Chamberlain said New Zealand, when compared to the top eight countries had the widest range of reading scores - reaching from the highest 5 per cent of performing students down to the lowest 5 per cent of performing students.

The survey also found that girls outperformed boys in reading in every participating country and maths results had not improved since 2003.

* NZ's overall reading ability is higher than the average but hasn't changed much since 2000.
* Only students in four other areas had better reading scores than New Zealand. Students in four other areas had higher scientific literacy.
* NZ has a disproportionate number of low achievers, especially Maori and Pasifika.