The United Nations secretary-general says he is deeply concerned by attacks by Islamic extremists in Burkina Faso and West Africa, urging a global response.

Ban Ki-moon spoke Thursday in Burkina Faso's capital, Ouagadougou. Extremists in January attacked a cafe and hotel here, killing at least 30 people in the first such attack in the capital. The violence closely mirrored the siege of an upscale hotel in Bamako, Mali in November that killed 20 people.

Burkina Faso also contributes troops to the U.N. mission in Mali, where five of its soldiers were killed by jihadists last year.

Ban said countries in the Sahel region, below the Sahara Desert, must address security issues, focusing on what causes instability, including poverty, unemployment, discrimination and impunity.

Ban is to travel to Mauritania next.