United Nations Secretary-General Antonio Guterres is visiting the world's deadliest U.N. peacekeeping mission on a trip to Mali.

The U.N. says the mission in the West African nation saw 21 peacekeepers and seven civilians killed last year, the fourth year in a row that it suffered the greatest loss of life among missions worldwide.

The U.N. mission has been the target of attacks by a number of extremist groups in Mali's vast north.

Guterres is expected to attend a ceremony paying tribute to the fallen U.N. peacekeepers and visit the command post for the recently created five-nation regional G5 Sahel counter-extremism force.

He also is visiting with President Ibrahim Boubacar Keita and other officials just two months before presidential elections.