United Nations leader Ban Ki-moon said on Sunday the Nairobi mall attack was a "totally reprehensible" act and that he has spoken with Kenya's President Uhuru Kenyatta.
In comments to reporters, Ban condemned the attack and hostage-taking, claimed by Somali militant group Shebab, "in the strongest terms."
"This premeditated act, targeting defenseless civilians, is totally reprehensible. The perpetrators must be brought to justice as soon as possible," he said, adding that he had spoken by phone with the Kenyan leader.
"This is a time of shock for all Kenyans and all - including the UN family - who are proud to call Nairobi home," Ban said.
Ghanaian poet and former UN envoy Kofi Awoonor, 78, is among 68 people killed in the attack.