The United Nations is looking to beef up its peacekeeping force in Mali, where implementation of a peace agreement between the government and rebels has dragged on and increasing attacks by extremists have made it the U.N.'s most dangerous on-going operation.

U.N. Special Representative for Mali Mahamat Saleh Annadif told the Security Council on Thursday that the security situation in the country has worsened significantly over the past weeks.

He said that between February and May 2016, 19 peacekeepers were killed in extremist attacks and that "so much of this loss of life could have been avoided if the contingents were better equipped."

Annadif asked the council to add some 2,500 troops to confront the extremist threat. He also called for more helicopters, drones and more robust rules of engagement.