Ukrainian President Volodymyr Zelensky on Friday, January 2, named military intelligence chief Kyrylo Budanov as the new head of his office, after his previous top aide resigned in November over a corruption scandal.

Budanov, 39, has built up a legendary reputation in Ukraine, credited with a series of daring operations against Russia since it launched an all-out assault against its neighbor in 2022. “I had a meeting with Kyrylo Budanov and offered him the role of the Head of the Office of the President of Ukraine,” Zelensky said on social media.

The nomination comes at a key moment in the nearly four-year war, with Zelensky announcing on Wednesday that a US-brokered deal to end the conflict was “90%” ready. “At this time, Ukraine needs greater focus on security issues, the development of the Defense and Security Forces of Ukraine, as well as on the diplomatic track of negotiations,” Zelensky said. “Kyrylo has specialized experience in these areas and sufficient strength to deliver results.”

Budanov said he had accepted the nomination and would “continue to serve Ukraine.” “It is an honour and a responsibility for me to focus on critically important issues of strategic security for our state at this historic time for Ukraine,” he said on Telegram.

Formal procedures to appoint him as the president’s chief of staff have been launched, Zelensky’s adviser Dmytro Lytvyn told journalists. When appointed, Budanov will replace Andriy Yermak, who resigned in November after investigators raided his house as part of a sweeping corruption probe.

Yermak was Zelensky’s most important ally, but a divisive figure in Kyiv, where his opponents said he had accumulated vast power, gate-kept access to the president and ruthlessly sidelined critical voices.

The four-year conflict, the deadliest on European soil since World War II, has killed tens of thousands and ravaged swathes of Ukrainian territory.