A top Ukrainian official at the heart of peace talks resigned after being thrust into the center of a massive corruption scandal, threatening to further weaken President Volodymyr Zelenskyy at a crucial moment in negotiations to end Russia's war.

Andriy Yermak, Zelenskyy’s powerful chief of staff, quit hours after his home was searched by investigators with Ukraine’s National Anticorruption Bureau, which is leading the $100 million kickback probe involving the country’s energy sector.