Nigeria has the highest number of out-of-school children in the world – about 10.5 million, according to UNICEF.

What it needs to do is to focus on improving its education system, and put more children in school.

This was the suggestion of a Nobel laureate, Malala Yousafzai on Monday during a visit to Nigeria.

Yousafzai, a Pakistani education activist who came to prominence when a Taliban gunman shot her in the head in 2012, was named a U.N. Messenger of Peace in April to promote girls' education. She has become a regular speaker on the global stage.

Addressing journalists in the capital Abuja after a meeting with the acting president, Yemi Osinbajo, Yousafzai said the government should declare a "state of emergency on education in Nigeria".

"They are happy to work more on education. We are also happy to hear positive response from the minister as well in ensuring that education is prioritised," she said, adding that spending on education at a federal and state level should be made public.

Nigeria's presidency did not immediately comment on the suggestions.

Recall that Yousafzai also campaigned to maintain awareness of the more than 200 schoolgirls who were abducted in 2014 from their secondary school by Boko Haram.

Yousafzai met some of the released girls in Abuja earlier on Monday, whom she described as being healthy. She appealed for the release of those who are still being held.