"Unfortunately, I must begin our meeting with [discussion of] yesterday's tragic event — the terrorist act committed against the Russian Federation represented by our Ambassador in the Turkish Republic Andrey Karlov," Shoigu said at a meeting with his Turkish counterpart Fikri Isik.
"We hope that a thorough investigation will be carried out and those guilty will be found and punished," he said.
"We will not stop in this struggle… and I am convinced we will achieve a result through joint efforts," he said.
Karlov was shot by a gunman at an art gallery exhibition opening in Ankara late on Monday. Doctors announced the ambassador's death 40 minutes after his hospitalization. The Russian Foreign Ministry said it considers the attack a terrorist act.