A helicopter crash Wednesday outside of the Ukrainian capital killed at least 15 people, including Interior Minister Denys Monastyrskyi.
Officials said the crash happened near a kindergarten in Brovary, a suburb east of Kyiv, where nine of the dead were on board the helicopter when it went down.
It was not immediately clear what caused the crash. Ukrainian President Volodymyr Zelenskyy said in a Telegram post he had directed authorities to investigate.
Zelenskyy called the crash a "terrible tragedy."
Officials earlier put the death toll at 18 people. Zelenskyy, in his post, said at least 15 people had died though the exact number of casualties was still being determined. He said at that point the dead included at least three children.
"The pain is unspeakable," Zelenskyy said.
"Tragedy far from the frontline, in Brovary," Ukrainian Foreign Minister Dmytro Kuleba tweeted. "My condolences to relatives of the victims, especially children."
Kuleba added that Monastyrskyi and Deputy Interior Minister Yevhen Yenin were "true Ukrainian patriots."
U.N. Resident Coordinator for Ukraine Denise Brown said she was "deeply saddened by the tragic deaths."
"I extend, on behalf of the United Nations, my deepest sympathy and condolences to their families, to the Government and to the people of Ukraine," Brown said in a statement.
European Council President Charles Michel expressed condolences to the Ukrainian people, calling Monastyrsky "a great friend of the EU."
"We join Ukraine in grief following the tragic helicopter accident in Brovary," Michel tweeted.
Asked by the President of the World Economic Forum at Davos, Borge Brende, if he thinks there will be an end to the Russian war in Ukraine this year, U.N. Secretary-General Antonio Guterres said Wednesday he does not see an end to the war in the immediate future.
"I do not see a chance at the present moment to have a serious peace negotiation between the two parties," Guterres said.
He said the solution needs to be based on international law and the respect of Ukraine's territorial integrity, and the conditions for that are not currently ripe.
Guterres said in the meantime, the United Nations is focusing its efforts on lessening the impact of the conflict on both the Ukrainian people and the international community.
He pointed to successes in extracting civilians earlier in the war from the Azovstal steel plant, the exchange of prisoners of war on both sides, getting international nuclear inspectors into Ukrainian facilities, and facilitating the exports of Ukrainian grain and Russian grain and fertilizer to international markets.
"So, we are trying to address the consequences," the secretary-general said. "But for the moment, I don't think that we have a chance to promote or to mediate a serious negotiation to achieve peace in the short term."
Of the global situation overall, including the fight against climate change, the 73-year-old U.N. chief was even more bleak.
"Let's be clear, I think we are in the worst situation I remember in my lifetime."
The United States and other Ukrainian allies are providing Ukraine with more advanced weaponry and training on those systems, and more aid is likely to be announced Friday as they convene the latest meeting of the U.S.-led Ukraine Defense Contact Group at Ramstein Air Base in Germany.
U.S. Defense Secretary Lloyd Austin will lead the talks, which will be attended by dozens of defense ministers, NATO Secretary General Jens Stoltenberg and Ukrainian Defense Minister Oleksii Reznikov.
On Thursday, Austin stops in Berlin to meet with incoming German defense minister Boris Pistorius as Germany considers approving its Leopard 2 battle tanks for Ukrainian forces.
Ukrainian President Volodymyr Zelenskyy said he discussed defense cooperation with German President Frank-Walter Steinmeier ahead of the Ramstein meeting. Zelenskyy did not mention the German tanks in his nightly address Tuesday.
Zelenskyy also thanked the Netherlands for what he said would be the addition of another Patriot missile battery for Ukraine's air defenses.
"So, there are now three guaranteed batteries. But this is only the beginning. We are working on new solutions to strengthen our air defense," Zelenskyy said.
Netherlands Prime Minister Mark Rutte said during a visit to the White House on Tuesday that his country has the intention to join what the United States is doing with Germany "on the Patriot project."
Germany and the United States each pledged to send a Patriot battery to Ukraine, and the U.S. Defense Department said Tuesday it had begun training Ukrainian troops to operate the advanced system.
Pentagon press secretary Brig. Gen. Pat Ryder told reporters the training at Fort Sill in Oklahoma "will last for several months and train upwards of 90 to 100 Ukrainians." (KB/VOA)