KYIV, Ukraine — Serhii Koretskyi, the state-energy company chief who was named as Ukraine ‘s new prime minister on Thursday, is not a typical choice to lead the government.

Unlike many of Ukraine’s senior government officials, Koretskyi, 48, did not climb through political parties, parliament or the civil service. A trained engineer, he built his career in business, spending more than two decades managing fuel and food industries before being picked to run some of Ukraine’s most troubled state-owned energy companies.

Quickly, he garnered a reputation as an effective crisis manager, reviving struggling state enterprises and making them profitable.

Now, he faces his biggest management challenge yet, one where business acumen alone will not be enough. Leading Ukraine’s cash-strapped wartime government will require political dexterity, diplomacy and power plays.

President Volodymyr Zelenskyy has tasked him with steering the country through what officials expect could be the hardest winter of the war due Russian attacks. He is Ukraine’s third prime minister since Russia’s full-scale invasion.

His premiership is already off to a rocky start. As lawmakers voted to confirm him, hundreds of protesters gathered in the city center, enraged at Zelenskyy and accused him of unfairly sidelining popular Defense Minister Mykhailo Fedorov in the sudden government reshuffle announced this week.

Koretskyi’s immediate priorities include protecting Ukraine’s battered energy system, stabilizing the economy, ensuring international aid is spent effectively and expanding domestic arms production, he said, addressing the parliament.

In 2022, after the government seized control of oil producer Ukrnafta and refinery operator Ukrtatnafta from oligarch Ihor Kolomoiskyi, Koretskyi was appointed to lead both companies simultaneously.

Within two years, Ukrnafta had reported record profits, cleared its tax debts and expanded production. The company became one of Ukraine’s largest taxpayers and a major contributor to the war effort, supplying fuel to the military and funding drones.

Last year Koretskyi was selected to lead Naftogaz, the state energy giant, at a troubled moment. Gas reserves had fallen to record lows after the previous management failed to secure sufficient imports and Russia intensified strikes on production facilities.

He launched an audit which triggered sweeping restructuring, eliminating overlapping functions and streamlining staffing in moves that drew criticism internally.

Under his leadership, Naftogaz rebuilt gas reserves to more than 13 billion cubic meters and raised nearly $1 billion.

Zelenskyy has described Koretskyi as “the most prepared candidate” for prime minister, highlighting his priority of being prepared for the winter.