U.S. Secretary of State John Kerry says he and his British counterpart are discussing a special initiative to deal with the Boko Haram (BOH'-koh hah-RAHM') extremist group in Nigeria and its neighbors.

Speaking in the Bulgarian capital on Thursday, Kerry said Boko Haram is "without question one of the most evil and threatening terrorist entities on the planet." He says their recent slaughter of hundreds of villagers in Nigeria's north is a "crime against humanity" and must be addressed.

Kerry said that during breakfast in Sofia with British Foreign Secretary Philip Hammond, they had talked about setting up a new initiative to address Boko Haram and the situation in Nigeria. He did not elaborate on the idea.