Credit…Metin Aktas/Anadolu Agency, via Getty Images

The helicopter crash that killed top Ukrainian officials on Wednesday created a vacuum at the top of a critical war ministry just as Kyiv prepares for a potential Russian offensive in the spring and suffers relentless long-range attacks on its civilian infrastructure.

Interior Minister Denys Monastryrsky, a trusted adviser to President Volodymyr Zelensky and responsible for the country’s internal security, was among at least 14 people killed when the helicopter crashed in Brovary, a small town on the outskirts of Kyiv on Wednesday. . Also killed, according to the Ukrainian parliament, were Yevhen Yenin, the first deputy minister of internal affairs, and Yurii Lubkovich, the ministry’s state secretary.

Calling each death “the result of war,” Zelensky linked the incident to the invasion of Russia, even as investigators assess whether mechanical failure, pilot error, sabotage, or another factor altogether caused the crash. Kyrylo Tymoshenko, deputy head of the Ukrainian president’s office, said the government officials on board had been traveling to a combat zone.

Whatever the cause, the impact of the crash is clear: a member of Zelensky’s inner circle, who had somehow managed to stay intact since the start of the war, is gone. And the disaster comes just as Kyiv renews a diplomatic push for some of the allies’ deadliest weaponry, as its main backers fear there is not enough time to allow the Ukrainian military to break the deadlock with Russian forces before Let Moscow launch another ground attack. .

The accident happened hours before Zelensky called on world leaders at the World Economic Forum in Davos, Switzerland, for more advanced weapons, including tanks and air defense missiles, and two days before defense ministers from the NATO and other officials meet in Ramstein. Air Base in Germany to discuss whether to send additional powerful tanks to help Ukraine’s defense efforts.

Mr. Monastryrsky, the highest-ranking government official to die since Russia invaded Ukraine last February, oversaw tens of thousands of Ukrainians fighting to defend their country as part of police, national guard and border units.

Mr. Monastryrsky, 42, also led rescue and recovery efforts this week in Dnipro, where a Russian missile killed 45 people in one of the deadliest attacks on civilians in the nearly year-long war.

In his late-night speech on Wednesday, Zelensky said Monastyrsky’s responsibilities had been reassigned and the country’s national police chief, Igor Klymenko, would head the ministry until a replacement is chosen.