The aircraft came down in Brovary, on the eastern outskirts of Kyiv, on Wednesday morning setting fire to a nursery packed with children.
Ukraine’s interior minister was among those killed in the tragedy.
According to the latest official toll, nine people on board and at least five on the ground lost their lives.
A child was among the dead while dozens of other people including many children were hurt, many of them suffering burns.
Olena Zelenska, wife of prime minister Volodymyr Zelensky, was visibly emotional as she was told of the tragedy while attending the World Economic Forum in Davos, Switzerland.
Three members of Ukrainian government – interior Minister Denys Monastyrskyi, his deputy Yevhen Yenin, and State Secretary of the Ministry of Internal Affairs Yurii Lubkovych – were among those killed.
Dabbing teary eyes and pinching her nose as she responded to the news, Mrs Zelenska said: “Another very sad day today — new losses.”
The Davos forum held 15 seconds of silence after opening the session to honour the Ukrainian officials killed.
It is not yet known whether the crash was an accident or a result of the war with Russia. No fighting has been reported recently in the Kyiv area.
“For now, we are considering all possible versions of the helicopter crash accident,” Ukraine’s prosecutor general, Andriy Kostin, said on social media platform Telegram.
An investigation is being carried out by the Security Service of Ukraine, he said.
Photos taken on Wednesday afternoon showed the scale of destruction caused by the crash, with large sections of building left charred and burnt out, and the helicopter’s mangled wreckage lying atop a crushed car.
Glib, a 17-year-old who lives nearby the crash site, told reporters at the scene on Wednesday: “We saw wounded people, we saw children. There was a lot of fog here, everything was strewn all around.
“We could hear screams, we ran towards them. We took the children and passed them over the fence, away from the nursery as it was on fire, especially the second floor.”
The crash came just four days after a Russian missile strike on an apartment building in southeastern Ukraine killed 45 people, including six children – marking the deadliest attack on civilians since the spring.
“Haven’t had time to recover from one tragedy, there is already another one,” said the deputy head of the Ukrainian presidential office Kyrylo Tymoshenko.
In London, Home Secretary Suella Braverman paid tribute to her Ukrainian counterpart Mr Monastyrsky on Twitter, where she said Ukraine had lost a “leading light” in its resistance against Vladimir Putin.
“This is truly heart-breaking. Interior Minister, Denys Monastyrsky was a leading light in supporting the Ukrainian people during Putin’s illegal invasion and when we spoke in October I was struck by his determination, optimism and patriotism,” she wrote.
“My thoughts go out to all those who have died in this horrible tragedy and their families. The UK will always stand with our Ukrainian friends.”