Andriy Yermak, the chief of staff to Ukrainian President Volodymyr Zelensky and a lead negotiator in peace talks with the U.S., has resigned, Zelensky said Friday.

In his nightly address, the Ukrainian president said he was "grateful" to Yermak "for always representing Ukraine`s position on the negotiation track exactly as it should be represented. It has always been a patriotic position."

Zelensky added that he will interview prospective candidates for the role Saturday.

Yermak, a longtime associate and aide of Zelensky, said Friday on Telegram that his home was searched by the National Anti-Corruption Bureau of Ukraine and the Specialized Anti-Corruption Prosecutor`s Office. The two agencies are probing whether Timur Mindich, another longtime Zelensky ally, led a group that laundered roughly $100 million in kickbacks from the Ukrainian energy sector.

Yermak`s former deputy, Andriy Smyrnov, was charged with illicit enrichment, money laundering and bribery last year, according to The Kyiv Independent. Kyrylo Tymoshenko and Rostyslav Shurma, two other former deputies to Yermak, have been investigated for corruption but have not been charged, the outlet reported.

The upheaval in Zelensky`s office comes as peace talks between the U.S. and Ukraine continue.

The Trump administration proposed a 28-point plan, crafted with Russian officials, to bring an end to Russia`s ongoing war to Ukraine last week, with the outline later tweaked upon input from Ukrainian and European officials.

President Trump told reporters on Air Force One on Tuesday that negotiators were "making progress" on an agreement. The president added that special envoy Steve Witkoff, and perhaps Trump`s son-in-law, Jared Kushner, will likely meet with Russian President Vladimir Putin in Moscow next week.

Putin, meanwhile, said Thursday that the administration`s peace plan could be the "basis" for a deal.

Zelensky noted in his Friday address that meetings between a Ukrainian delegation - including Andrii Hnatov, the chief of general staff of the country`s armed forces, and others - and U.S. officials "will be held very soon."