Officials from Ukraine’s interior ministry announced the investigation in a televised briefing, citing a trove of documents released by House Democrats on Tuesday that included several cryptic WhatsApp messages between Lev Parnas and Robert Hyde that discussed monitoring Yovanovitch’s physical movements and electronic devices.

“Ukraine’s position is to not interfere in the domestic affairs of the United States,” an interior ministry official said. “However, the published records contain the fact of a possible violation of the legislation of Ukraine and the Vienna Convention on Diplomatic Relations, which protects the rights of a diplomat on the territory of another country.

“Ukraine cannot ignore such illegal activities on its territory.”