Students in China have emerged as the world's top performers in mathematics and science in an international assessment measuring how well education systems prepare 15-year-olds for the challenges of the future as Singapore ranked second in both subjects.

More than half of 15-year-olds did not achieve the national proficiency standard in maths, according to new PISA results, which show China and Singapore in the lead.

Singapore placed second in the world behind Macau and ahead of Beijing, Shanghai, Jiangsu and Zhejiang in China.

Japan, South Korea and Hong Kong slip as regional rivals dominate OECD assessment