In his statement on Wednesday, Kenyan President Uhuru Kenyatta said "Kenya mourns with the people and government of Belgium following the heinous terrorist attacks on Tuesday".
He called on the international community to fight against "extremist enemies", Xinhua reported.
Somali President Hassan Sheikh Mohamud termed the attacks as "barbaric" and "an affront to humanity".
"We join the world in condemning the brutal attacks of civilians in Brussels. We grieve with those who have lost loved ones. We pray for the families affected," Hassan Mohamud said in a statement.
Hassan Mohamud said terrorism is a global threat, requiring collective responsibility, adding Somalia, a country suffering from Islamist militant group Al-Shabaab, continues to work closely with the international community to eradicate extremist groups.
Blasts ripped through Zaventeen Airport and a metro station in Brussels on Tuesday morning. The Islamic State (IS) has claimed responsibility.