The cause of the crash, which comes as the country’s war with Russia approaches the 11-month mark, was not immediately clear.
At least nine of those killed had been onboard the emergency services helicopter when it crashed in Brovary, a suburb about 15 miles northeast of the capital, Ihor Klymenko, the head of the national police, said in a statement.
He said the dead included Ukrainian Interior Minister Denys Monastyrsky, his deputy, Yevhen Yenin, and Yurii Lubkovych, the state secretary. One child was also among the dead, officials said.
Officials had earlier put the death toll at 18, including four children, but it was later revised down as authorities stressed the final figure was uncertain.
“The pain is unbearable,” President Volodymyr Zelenskyy said.
“May all those whose lives were taken this black morning rest in peace!” he said in a statement.
At least 25 people, including 11 children, were being treated in hospitals, officials said. The extent of their injuries was not immediately clear.
The helicopter fell near a kindergarten and a residential building, according to Oleksii Kuleba, the head of the Kyiv Regional Military Administration.
“At the time of the tragedy, children and employees of the institution were in the kindergarten. At this point, everyone was evacuated,” he said.
Video and photos shared online by Ukrainian officials showed flames bursting from at least one building as smoke billowed from the crash site.
The Security Service of Ukraine said on its Telegram channel that it was considering at least three possible causes, including malfunction, a violation of flight rules or “deliberate actions to destroy the vehicle.”