Nigeria's president has appealed for international help to find, and ensure the release of, 276 schoolgirls abducted by suspected Boko Haram fighters, amid criticism over government inaction.

Goodluck Jonathan said on Sunday that he had sought help from the US President Barack Obama, and also approached other world powers including Britain, France and China for help on security issues.

"This is a trying time for this country... it is painful," he said, and pleaded for the cooperation of parents, guardians and the local communities in the rescue efforts.

"We will get over our [security] challenge," he stated, adding that Nigerians were "justified if they expressed their anger against government" over the perceived slowness in rescuing the girls who were kidnapped from their hostel in Chibok town, in northeast Borno state, on April 14. 

He assured that the "disappearance" of the girls would not be another global "mystery" in reference to the missing Malaysian passenger jet that has not been found despite the vast multi-national search deployed.

US promises help

On Saturday, US Secretary of State John Kerry promised help. "The kidnapping of hundreds of children by Boko Haram is an unconscionable crime, and we will do everything possible to support the Nigerian government to return these young women to their homes and to hold the perpetrators to justice," Kerry said from Addis Ababa, Ethiopia.

Jonathan met for the first time with all the stakeholders on Saturday, including the principal of the Chibok Government Girls Secondary School in northeastern Nigeria where the girls and young women were kidnapped in a pre-dawn raid on April 15, presidential adviser Reuben Abati told reporters.

Nigerians' anger at the failure to rescue the students, and protest marches last week in major Nigerian cities as well as New York City, have spurred to action Jonathan's government, which many see as uncaring of the girls' plight.

Unverified reports suggested that some of the girls were sold into marriage with their abductors for $12.

Nii Akuteh : 'Boko Haram are the prime suspects'

Some of the girls were taken across Nigeria's borders to Cameroon and Chad, parents said last week, quoting villagers.

Anguished parents in Chibok town, who have lost confidence in the government and military, have been begging for international help. 

The mass kidnapping is one of the most shocking attacks in Boko Haram's five-year offensive, which has killed thousands across the north and centre of the country, including 1,500 people this year alone.

Boko Haram, an armed group whose name means "Western education is sinful", is fighting what it calls Western influence and wants to form an Islamic state in Africa's largest oil producer country.

Source: Al Jazeera and agencies