(Adds comment by Australian ambassador, paragraphs 3-4)
By Michelle Nichols
UNITED NATIONS, May 22 (Reuters) - The U.N. Security Council committee on al Qaeda sanctions blacklisted Nigeria's Islamist militant group Boko Haram on Thursday after the insurgents kidnapped hundreds of schoolgirls, diplomats said.
Nigeria, which until recently had been reluctant to seek international help to combat Boko Haram, requested earlier this week the group be sanctioned. As a result, it is now subject to an international asset freeze, travel ban and arms embargo.
"What will the practical impact of that be? Hard to say but it's an essential step we had to take," said Australian U.N. Ambassador Gary Quinlan, al Qaeda sanctions committee chair, adding that the aim was to "dry up support" for the group.
"We will work to try and make sure that anybody supplying any material assistance to Boko Haram - whether funding or arms - will in fact be stopped, will be deterred by the fact they too will be eligible for listing on the sanctions list," he said.
Boko Haram kidnapped more than 250 girls from a secondary school in Chibok in remote northeastern Nigeria on April 14 and has threatened to sell them into slavery. Eight other girls were taken from another village earlier this month.
Boko Haram, which in the Hausa language means broadly "Western education is sinful," is loosely modeled on the Taliban movement in Afghanistan.
"Today, the Security Council took an important step in support of the government of Nigeria's efforts to defeat Boko Haram and hold its murderous leadership accountable for atrocities," U.S. Ambassador to the United Nations Samantha Power said in a statement.
"By adding Boko Haram to the U.N.'s 1267 (al Qaeda) sanctions list, the Security Council has helped to close off important avenues of funding, travel and weapons to Boko Haram, and shown global unity against their savage actions," she said.
Boko Haram's five-year-old insurgency is aimed at reviving a medieval Islamic caliphate in modern Nigeria, whose 170 million people are split roughly evenly between Christians and Muslims. The group is becoming, by far, the biggest security threat to Africa's top oil producer.
The U.N. listing entry describes Boko Haram as an affiliate of al Qaeda and the Organization of al Qaeda in the Islamic Maghreb (AQIM).
"Boko Haram has maintained a relationship with the Organization of al Qaeda in the Islamic Maghreb for training and material support purposes," according to the narrative summary accompanying the listing.
"For example, Boko Haram gained valuable knowledge on the construction of improvised explosive devices from AQIM. A number of Boko Haram members fought alongside al Qaeda affiliated groups in Mali (in) 2012 and 2013 before returning to Nigeria with terrorist expertise," it said. (Editing by Meredith Mazzilli, Cynthia Osterman and Eric Walsh)