England and Northern Ireland have gained top 10 places in new international reading rankings.
The latest Progress in International Reading Literacy Study (PIRLS) puts Northern Ireland in joint sixth place, while England is joint eighth.
Russia scored the highest result, with an average score of 581, taking top place out of the 50 countries that took part in the tests, which measure the reading levels of 10-year-olds.
Second was Singapore with an average score of 576, followed by Hong Kong (569), the Republic of Ireland (567) and Finland (566).
The rankings show that Northern Ireland had an average of 565, the same as Poland, while England had an average score of 559, the same as Norway and Chinese Taipei.
School Standards minister Nick Gibb said England's position was due to a focus on phonics - which teaches children to read using sounds - in the nation's schools.
"Today's results put the success of our increased emphasis on phonics and continued focus on raising education standards on a global scale," he said.
"Thanks to the hard work of teachers across the country, 154,000 more six-year-olds are reading better than ever before - this is fundamental to our ambition of helping every child fulfil their potential.
"Our rise through the global rankings is even more commendable because it has been driven by an increase in the number of low-performing pupils reading well. This demonstrates our determination to ensure this is a country that works for everyone, regardless of background."
Geoff Barton, general secretary of the Association of School and College Leaders, said that the results were due to the focus schools have placed on reading.
"It's great news that England and Northern Ireland have done so well in this international study, and congratulations to teachers and pupils," he said.
"This is the result of the huge focus that schools have placed on the teaching of reading over the course of many years, ensuring that it is emphasised from an early age and putting it at the heart of the curriculum."