Schools minister Nick Gibb has defended tests for primary school children saying they exist to hold schools to account and that "no child should be put under stress" by the assessments.
The Tory minister had come under criticism from parents who said that children were being over-tested.
At the annual conference of the Boarding Schools' Association (BSA) in Manchester he told delegates that tests ensured that young people were leaving primary school literate and numerate and "on a par with the best performing countries of the world".
He said: "Primary school assessments are there to hold schools to account, they have no real consequences for the young people taking them, they are not qualifications. The assessments are there to ensure that we are holding schools to account; that every school is delivering quality education."
Mr Gibb, MP for Bognor Regis and Littlehampton, added that he was "confident" that schools were "very well prepared" and were "teaching the curriculum very successfully" despite some schools themselves saying pupils were tested too hard.
He appeared via videolink at the conference after saying that he had been held up in the House of Commons.
Beforehand Mr Gibb tweeted: "Sorry not in Manchester for the Boarding School Association Conf but looking forward to speaking via video link @BSAboarding #BSAconf2016".
On being introduced, chairman Paul Spencer Ellis apologised for Mr Gibb's absence in person, joking that he was his "grammar double".
The comment came after Mr Gibb had tripped up on a grammar question on BBC Radio 4's World At One, where he was quizzed over concerns that Sats tests for primary school children were too prescriptive.
In protest at the controversial exams, some parents kept their children off school on Tuesday.
The Let Our Kids Be Kids campaign organised the day of action in protest at children being "over-tested, over-worked and in a school system that places more importance on test results and league tables than children's happiness and joy of learning".
Mr Gibb said: "We are introducing more rigorous new tests at primary schools - this has led to the claim that English pupils are the most over-tested in the world - a claim which any inspection of international evidence shows is unfounded.
"Tests at the end of primary school are absolutely imperative in ensuring that all pupils are equipped with numeracy and literacy which enables them to thrive at secondary school. This isn't currently the case."
He said that in countries such as South Korea and Singapore the proportion of "functionally literate and numerate" pupils aged 15 is over 90% in comparison to England where only 82% of pupils are functionally literate aged 15, and 77% functionally numerate.
"This Government is committed to the belief that all children if taught well can achieve," he said, adding that the importance of academic attainment is something that the Department for Education and the BSA share.
Mr Gibb was quizzed on what he was doing to help unaccompanied refugee children coming into the UK to access high quality education, ensuring that they too were numerate and literate.
National director of the Boarding Schools' Association Robin Fletcher said it had been in communication with the Government about fully-funded school places for unaccompanied refugees - of which there are around 80 available - but that there had not been any uptake.
He added that the boarding school sector was "poised to help".
Mr Gibb said that it had been an "important offer" by the boarding schools.
He added: "In terms of refugees, the BSA schools have made offers of places for refugees for their school, information about the offer - including help and guidance provided by the BSA - has been shared with regional strategic migration partnerships who are working with the Government's resettlement team to coordinate all of the offers.
"This is to ensure that these offers are directed at local authorities which will be resettling or have already resettled refugees."
He added that he was "very grateful" for the offers being made.
The Government recently announced a new policy to resettle "children at risk" from the Middle East and North Africa region which encompasses unaccompanied children, those separated from their parents and other vulnerable children.
In a statement, they said they were working with local authorities that are in the process of resettling Syrian refugee families and unaccompanied asylum seeking children to ensure support is given.
A spokesperson for the Government said: "Far from shunning this generous offer, the Syrian Resettlement Programme has ensured that the BSA's offer of free boarding school places has been promoted and made available to all councils engaged in resettling Syrian refugee families and unaccompanied asylum seeking children in the UK.
"We are working with councils to ensure children are given the support they need and it is for councils to decide which schools to place these children in."