In this handout photograph taken and released by the Ukrainian Presidential Press Service on June 3, Ukraine's President Volodymyr Zelensky, right, and NATO Secretary General Mark Rutte lay flowers at the Wall of Remembrance of the Fallen for Ukraine in Kyiv, amid the Russian invasion of Ukraine. AFP-Yonhap

Ukrainian President Volodymyr Zelensky accused Moscow on Sunday of deliberately targeting the exclusion zone around the decommissioned Chernobyl nuclear power plant, after a drone struck a building at the central storage facility for nuclear fuel.

He described the overnight incident as an "extraordinarily treacherous Russian attack."

The Ukrainian Foreign Ministry, Energy Ministry and other relevant offices were informing Kiev's partners about the incident, Zelensky wrote on Telegram.

"Russia deliberately struck precisely this nuclear infrastructure facility," Zelensky said. While radiation levels had not exceeded permitted limits, he said there had been "an excess of Russia's already sky-high audacity."