Michelle Obama is set to highlight the importance of education on a trip to Oxford University today.

The US first lady is due to visit the elite institution on Wednesday afternoon and will catch up with pupils from the all-girl Elizabeth Garrett Anderson School (EGA).

Mrs Obama first met pupils from the north London secondary school when she accompanied US president Barack Obama on their first visit to London in April 2009.

She made a surprise trip to the school, where she urged the young women to "be the best that you can be" and to have "confidence and fortitude" to determine their own success.

Around 35 EGA pupils are due to take part in a day-long "immersion experience" at Oxford, including campus tours, career discussions and mentoring sessions, before meeting Mrs Obama.

The trip, which has been arranged at Mrs Obama's suggestion, has been designed to teach the girls about university and encourage them to think about studying for a degree.

Since visiting EGA two years ago, Mrs Obama has kept in touch with the school, writing letters and encouraging the girls in their studies.

In February last year a group of London students, including one from EGA, were invited to the White House after winning a US Embassy Black History Month essay contest.

Oxford vice-chancellor Professor Andrew Hamilton said: "We look forward immensely to welcoming the First Lady to the university, and to sharing with her and the EGA students something of what makes Oxford and the education it offers so special."

EGA has been rated as "outstanding" by Ofsted. Around nine in ten of the school's pupils are from ethnic minority backgrounds, with 55 languages spoken by the pupils, and around 60 per cent speaking English as an additional language.