Abuja - More than 200 schoolgirls on Wednesday began their second month as Boko Haram hostages as international powers ramped up efforts to track down the savage group.
Lawmakers began debating a request from President Goodluck Jonathan for a six-month extension to a state of emergency first imposed in three northeast states worst affected by the violence exactly a year ago.
A total of 223 of the 276 girls who were abducted from their school in the remote town of Chibok, Borno state, on April 14 are still missing. Street protests were held to mark the one-month anniversary of their kidnapping.
In London, British Prime Minister David Cameron told parliament that a Sentinel surveillance aircraft and a military team will be sent to Abuja as part of the international rescue operation.
In Paris, President Francois Hollande's office said the leaders of Benin, Cameroon, Niger and Chad would meet with Nigeria's President Goodluck Jonathan in the French capital on Saturday for a security summit.
Representatives from the European Union, Britain and the United States would also attend, the Elysee said.
"The meeting will discuss... how to cut off (Boko Haram) by intelligence, how to train to fight and drive out the killers," Foreign Minister Laurent Fabius added.
"France is not taking anyone's position but our role is to help Africans ensure security because there can't be any solution without democracy, development and security." - Open to talks -
On Monday, Boko Haram released a video purporting to show about 130 of the missing girls and claimed they had converted to Islam. All of them were later identified as attending the school that was attacked in Chibok.
The Islamist group's leader, Abubakar Shekau, suggested they could be freed in a prisoner exchange.
Special Duties Minister Taminu Turaki has said the government had always been willing to talk with the insurgents.
Nigerian Nobel laureate Wole Soyinka, however, doubted that talks would make headway, suggesting Boko Haram's leader was incapable of dialogue.
The winner of the 1986 Nobel Prize for Literature told AFP by phone from Los Angeles that Shekau was "high on religion and drugs".
"For me, we are dealing with a sub-human species," he said. "How do you dialogue with that kind of obscenity?"
Jonathan and his government have been widely criticised for their slow response to the kidnapping.
But they were forced to react in the face of a growing social media campaign that has won wide support across the world and contributed to international pressure.
Specialist US, British, French and Israeli teams have been sent to help in the search operation, which Nigeria's military has said is concentrated on the Sambisa forest area of Borno state.
There are fears, though, that the girls may have been split into groups and taken into neighbouring Chad or Cameroon, which Boko Haram has used as bases to launch attacks and safe havens in the past. - Special powers -
Nigeria's senators summoned the ministers of defence and police affairs, as well as military and security chiefs, to brief them about the application to extend the state of emergency on Thursday as the issue was discussed in the lower House of Representatives.
By law, the request has to be approved by two-thirds of both of chambers.
"It is the tradition of the Senate to appraise and assess the performance of the state of emergency before we debate" any further extension, said Senate majority leader Victor Ndoma-Egba.
Jonathan is facing calls to explore a negotiated settlement with Boko Haram given the apparent lack of progress in curbing the violence after the state of emergency was imposed on May 14 last year.
Initial gains from a surge of troops to Borno, Yobe and Adamawa states, tighter security, as well as measures such as curfews and cutting the mobile phone networks, appear to have been lost.
Attacks have increased on rural areas leading to mounting civilian casualties. More than 1,500 are estimated to have been killed this year alone.
Security analysts have urged Nigeria to improve its counter-insurgency tactics including more use of intelligence, instead of just conventional means, to defeat guerrilla fighters.
The head of the US Africa Command, General David Rodriguez, met Nigerian top brass in Abuja on Monday to discuss the search, as well as overall military cooperation.
International military leaders hope their expertise could help refine Nigeria's tactics against Boko Haram.
The former deputy director of Israel's overseas intelligence agency Mossad, Ilan Mizrahi, said Nigeria needed to work more closely with neighbouring powers to tackle the wider threat posed by the group.
"They have to cooperate with Niger, they have to cooperate with Cameroon. You have to have regional cooperation. I think the Western powers... (should) try and upgrade the military intelligence of the Nigerians," he added.
Jonathan said on Tuesday that the security situation was "daunting" in the northeast and that he was concerned by the increasing loss of civilian life.
The governor of Yobe state, however, voiced his opposition to extending the state of emergency and it is likely that Borno and Adamawa will follow suit.
All three states are run by the main opposition All Progressives Congress party, which is eyeing power in next year's general election.