Reforms to take years to bear fruit
Education Secretary Michael Gove said it would be 10 years before his schools reforms result in English students climbing the international league tables.
He insisted early signs of improvement could be measured in more schools taking on academy status and greater numbers of pupils pursuing rigorous subjects like history, geography, languages and sciences.
However he said reversing England's slide in league tables for reading, maths and science would not be seen for a decade as the next updates would judge pupil performance under Labour's education policies.
"I think we do need to climb up that league table but I think it will take 10 years before we begin to see the fruits of all the reforms we are making which will lead to a turnaround in league tables like that," he told BBC1's Sunday Politics.
Mr Gove said "grade inflation" was a major cause of the increasing numbers of students gaining higher grades at GCSE and A level over the past 15 years and that exams had to be made tougher.
The idea of limiting the number of students that could be awarded each grade had "merit", he said, and could promote confidence in exam standards. The suggestion is currently being discussed with universities.
"The question I'm asking universities at the moment is how can we make A levels more rigorous. This is one idea to set the ball rolling," he said.
"We have got to tell the truth about these things. When people see that the number of Firsts and 2:1s at university have grown exponentially, and people see pass rates increase at this level, they know schools have improved but they haven't improved at that rate, so it discredits the integrity of our education system."
If tougher exams meant fewer pupils got As and A*s, he said, then that was something the Government would "have to accept".
"But I want to ensure that as well as exams being tougher that schools work harder and I think what we will see is our exams once again trusted across the globe and our children among the best in the world."