Image caption In 2016 Wales scored 478 in maths, 477 in reading, and 485 in science

A key target to improve Wales' scores in global education tests has been dropped by the Welsh Government.

Ministers wanted to see Welsh pupils achieve a score of 500 in every subject by 2021 in the Pisa tests.

But Education Secretary Kirsty Williams told a committee of AMs: "It's not my target".

Introduced in 2014, the target replaced the previous aim of seeing Wales ranked among the top 20 best-performing countries by 2015.

Students in Wales were the lowest of the UK nations in science, reading and maths in the 2016 tests, scoring 478 in maths, 477 in reading, and 485 in science.

The Pisa tests - a major study of educational performance - are taken by 15-year-olds in 72 countries every three years.

After the 2016 results - the fourth time Wales had done worse than the other UK nations - First Minister Carwyn Jones admitted that the results made for "uncomfortable reading".

Image caption Kirsty Williams: It's a much more complex picture

In a meeting of the assembly's Children, Young People and Education Committee on Wednesday, the education secretary was asked by Plaid Cymru education spokesman Llyr Gruffydd whether the Welsh Government still retained the 500 score target.

Ms Williams said: "I have been clear that my expectation is for the Welsh education system to make progress in the Pisa scores. But, as I said, it's more complex than that.

"We need to make progress in specific areas. We have made progress for our lower performing children that we've raised them up and they're doing better than the OECD average.

"So, it's a much more complex picture [than] just saying we're going to have this individual target."

'Lowering expectations'

Mr Gruffydd pressed the education secretary, asking: "So the target now isn't the stated aim of 500, it's to move in the right direction?"

"It's not my target," Ms Williams replied.

The Plaid AM said it showed that "instead of rising to the challenge, the cabinet secretary is lowering expectations".

"There is no reason why children in Wales cannot achieve as well as other UK nations," he said.

Conservative education spokesman Darren Millar accused the Welsh Government of lacking ambition and presiding over a "decade of decline" in the Pisa assessments.

"To climb high we must first aim high," he said.

"If Wales is to rise up the rankings and compete with the world's very best education systems then we need an ambitious target, and a clear strategy to deliver that target."

But there was support for the education secretary from the National Union of Teachers (NUT), which said it had "never subscribed to the notion of setting arbitrary Pisa targets".

NUT Cymru policy officer Owen Hathway said: "It is far more important to look at how we support teachers and pupils in their workload pressures, professional development and with the right funding and resources rather than chasing targets which mean very little to individual pupils."