“All emergency services are on the scene. Everyone affected will receive the necessary assistance,” Zelensky added in a message on Telegram.
“I instructed Poklad to deliver an appropriate, tangible response and, where possible, one that mirrors this strike, to the Russians once everything is ready. Our military will support this response.”
Images of the office widely shared online showed black smoke pouring from two windows on the front of the building.
Foreign Minister Andriy Sybiha said the attack was a “major escalation that demands resolute responses”.
“Moscow launched this strike during a renewed push for peace – laying bare its true rejection of diplomacy,” he added.
Kyiv Mayor Vitali Klitschko said five people had been hurt in the SBU attack, but did not elaborate on whether they were inside the offices.
The Russian defence ministry also said on Friday it had struck a cargo vessel in the Ukrainian port of Chornomorsk and a tanker near Odesa.
In recent weeks Russia has escalated its daytime strikes on Ukrainian targets.
In many instances it has employed jet-powered drones which are faster and harder to intercept. It is not yet known which type of munition was used in this latest attack.
