NAIROBI, Kenya (AP) — Kenya's President Uhuru Kenyatta says the fight against extremism will be the key topic of talks with U.S. President Barack Obama, who will be visiting the country of his father later this week.

Kenyatta said Tuesday that his country has been working closely with American security agencies in the fight against extremism and he hopes his meeting with Obama shall further strengthen this cooperation.

Kenya is battling a wave of extremist attacks by al-Qaida-linked al-Shabab militants from Somalia that has killed more than 400 people since October 2011 when the country sent troops into Somalia to fight the militants.

Al-Shabab has vowed to avenge Kenyan military presence in Somalia.