Muhammadu Buhari - who made security a cornerstone of his 2015 election win and could face voters again next year - promised a rennewed offensive against Boko Haram militants and defended his government’s record on limiting their territory.

“I’ve directed the army, air force, police, DSS and the rest of the security agencies to find the girls wherever they are,” he said at the start of tour of security hotspots across Nigeria.

Security has become a politically charged issue with less than a year until the next election, scheduled for February 2019. Buhari has not said if he will seek a second term.

The attack on the town of Dapchi in Yobe state on Feb. 19 was the biggest mass abduction since Boko Haram took more than 270 schoolgirls from the town of Chibok in 2014.

Earlier in the day, Buhari told people in Yobe’s state capital, Damaturu, that the government would not rest until the last girl kidnapped by insurgents has been released.

Boko Haram, which has killed tens of thousands of people since 2009 in its bid to create an Islamic state, lost most of its territory in the face of an offensive by Nigeria’s army backed by troops from neighbouring countries in early 2015.

But factions of the group have continued to carry out suicide bomb attacks and gun raids in the northeast, Cameroon, Niger and Chad.

Buhari told the audience Boko Haram had controlled large parts of the northeast before the crackdown. “But now, they only resort to bombing, killing, brainwashing young girls for bombing in mosques, churches, markets and motor parks.”

That marked a shift from past statements when he had said Boko Haram had been totally defeated.

The 75-year-old former military ruler promised a new push in the offensive. “Federal government will use all its power to direct the Nigerian Army, air force and all security agencies to see to the end of insurgency and bring peace to the country,” he said.

Nigeria has also seen clashes between herders and farmers in other areas in recent months and is trying to maintain a fragile peace in the Niger Delta where militant attacks on oil facilities helped to push Africa’s biggest economy into a recession in 2016.

The abduction of girls from Chibok caused international outrage and criticism of then president Goodluck Jonathan for his handling of the attack, contributing to his election defeat.