Ukrainian president Volodymyr Zelensky has said there are "no accidents at war time" after 14 people died in a helicopter crash in the capital, Kyiv, APA reports citing BBC.
Ukraine has not claimed Russian involvement, but Mr Zelensky told the World Economic Forum in Davos the tragedy was a consequence of the war.
Interior Minister Denys Monastyrsky died, alongside several colleagues.
Mr Zelensky also used his video address to urge allies to quickly send more weapons before new Russian offensives.
"The time the free world uses to think is used by the terrorist state to kill," he explained. The remark was interpreted as a request for Germany to hurry along a delivery of its much-coveted Leopard tanks.
Berlin has reportedly been unwilling to send the vehicles unless the US commits to providing its own Abrams battle tanks. The UK recently pledged to send a number of its own tanks to Kyiv.
The head of the Nato military alliance said at Davos on Wednesday that Ukraine could expect to receive "more support, more advanced support, heavier weapons and more modern weapons".
Jens Stoltenberg said Nato's member states would meet on Friday to discuss what military equipment could be sent to Kyiv.