President Goodluck Jonathan has met parents of 219 kidnapped Nigerian schoolgirls and dozens of classmates who managed to escape from their Islamic extremist captors.

Jonathan assured them of his determination that those still in captivity "are brought out alive", presidential spokesman Reuben Abati told reporters after the meeting.

It was "a very successful event," said Abati. Some of the girls described their escapes and Jonathan gave assurances that the education of the girls and their still-captive classmates would not suffer in any way, he said.

"Mr. President reassured them of the federal government determination and his personal determination to ensure that the girls that are still in captivity are brought out alive. He made it clear that is the main objective of the government," said Abati.

The parents emerged from the closed door meeting without showing emotion but some shook hands with the president. Some of the escaped schoolgirls smiled for photographers after the meeting.

Journalists were prevented from speaking to the girls and the parents by Nigerian security.

The delegation of 177 people met Jonathan, said Lawan Abana, spokesman for the community of Chibok, the town where the schoolgirls were kidnapped. An AP reporter counted 51 of the 57 girls who escaped after their abduction on 15 April.

At least 11 of the parents have died since the kidnappings – seven in a village attack this month and four of heart attacks and other illnesses that the Chibok community blames on the trauma, according to residents.

Jonathan was accompanied in the meeting by the ministers of education and finance, and his national security adviser. Also present was the governor Kashim Shettima of Borno state, from which the girls were abducted. Shettima has accused Jonathan of not doing enough to save the girls and has angered the government with his charges that Boko Haram fighters are better armed and motivated than Nigeria's military.

Tuesday's meeting came after some parents refused to meet Nigeria's leader last week. For months the parents have been asking to see the president and he finally agreed to a request from Pakistani girls-education activist Malala Yousafzai, who had met with the parents.

Jonathan blamed activists of the #BringBackOurGirls campaign for politicizing the abductions and influencing the parents. The parents said they needed time to decide who would attend.

The failure of Jonathan's government to rescue the girls has prompted an international campaign and daily #BringBackOurGirls rallies in Abuja, the capital, to ensure attention for the girls' plight.

Some of the parents and community leaders of Chibok have made public statements urging Jonathan to negotiate with the girls' captors. Boko Haram is demanding release of detained fighters in exchange for the girls. So far, Jonathan has refused. Nigeria's Defense Ministry, also criticized for not quickly rescuing the girls, has said that it knows where they are being held but that it fears any military campaign could get them killed.

Boko Haram has increased the number and deadliness of its attacks and this month has been closing in on Chibok, threatening to attack again, according to community leaders.

Last week Boko Haram fighters took control of Damboa town, strategically located at a crossroads about 20 kilometers (12 miles) from Chibok, and the National Emergency Management Agency said Monday more than 15,000 people from the town and nearby villages are on the run.