Nigerian President Muhammadu Buhari predicted Tuesday that Boko Haram would be defeated by a new African force within 18 months as the World Bank said $2.1 billion in loans could be made available to rebuild areas devastated by the militants.

Buhari said in an interview with The Associated Press that the militants would be routed with the help of troops from Benin, Chad, Cameroon and Niger as part of the Multi-National Joint Task Force, which Buhari said would be ready to launch operations at the end of the month.

Boko Haram's Islamist insurgency has killed more than 13,000 people since 2009 and displaced an estimated 1.5 million others.

"We are going to deny them recruitment. We are going to deny them free movement across borders. We are going to deny them training. We are going to deny them receiving reinforcements in terms of equipment," said Buhari.

Boko Haram in March declared allegiance to the Islamic State group and Buhari has said it also has links with Islamist militants in northern Mali.

But he conceded that Nigerian authorities lack any new information about the hundreds of schoolgirls still missing after a mass kidnapping in the northern town of Chibok in April 2014. The abductions sparked international outrage and a global "Bring Back Our Girls" campaign that reached as far as the White House, with First Lady Michelle Obama lending her support.

Dozens of schoolgirls escaped in the days after the abduction but 219 remain missing.

"I think Nigeria will make as much sacrifice as humanly possible to get the girls back. This is our main objective," Buhari said, a day after meeting with President Barack Obama.

Buhari said his government was even open to freeing detained militants in exchange for the girls' freedom, but only if it can find credible Boko Haram leaders to negotiate with.

"We just can't say yes or no in a sort of impulsive manner. We have to establish the facts before we agree" to negotiations, he said.

Boosting trade, security links

Buhari also met with representatives from the World Bank, the Bill and Melinda Gates Foundation, and the World Health Organization on his visit to Washington this past week. A World Bank spokeswoman said that $2.1 billion could be lent to Nigeria from the bank’s development agency and would be interest-free for the first 10 years.

“Apart from rebuilding the region in terms of infrastructure, priority must also be given to the resettlement of internally displaced persons, who now number over one million,” Buhari said in a statement.

Buhari’s US visit comes two months after he took office upon defeating Goodluck Jonathan in March elections, a victory based largely on the failure of his predecessor to stem the insurgency.

A former general himself, Buhari fired the military chiefs of the once-mighty Nigerian army last week, accusing them of corruption.

His early visit to Washington is a sign of the importance the US grants to good relations with Nigeria, Africa’s largest economy and biggest oil producer. Obama said on Monday that the US also wants to cooperate more closely with Abuja on counter-terrorism.

Buhari met Tuesday with chairman of the Joint Chiefs of Staff General Martin Dempsey and CIA Director John Brennan to request more US help against Boko Haram.

"The United States is very clear of the situation. What we need is intelligence, we need training facilities, we need some equipment," Buhari told AP.

But Buhari also acknowledged US concerns over allegations that the Nigerian military has committed human rights abuses, including in the fight against the Islamist insurgency. Amnesty International has accused the army's leadership of complicity in the death of 8,000 detainees in the campaign against Boko Haram.

Washington’s unease over the allegations prompted it to block the sale of US attack helicopters to Nigeria last year. But Buhari said this week that his new military chiefs were retraining their forces and would adhere to internationally acceptable rules of engagement in the future.

(FRANCE 24 with AP and REUTERS)