The head of the U.N. nuclear watchdog called for the release of the director-general of Ukraine's Russian-occupied Zaporizhzhia nuclear power plant, saying his detention posed a threat to safety and security.
A Russian patrol detained Ihor Murashov on Friday, the state-owned company in charge of the plant said on Saturday, and the International Atomic Energy Agency said Russia had confirmed the move.
"IAEA Director General Rafael Grossi expressed the hope that Mr Murashov will return to his family safely and promptly and will be able to resume his important functions at the plant," the agency tweeted late on Saturday.
Ukraine's President Volodymyr Zelenskiy said Murashov was abducted by Russia and called it an act of terror.
"This is another instance of clear act of Russian terror, for which the terrorist state must bear an ever-increasing punishment," Zelenskiy said in his nightly video address.
The IAEA has been in contact with relevant authorities seeking clarifications on his temporary detention, which it said had a "very significant impact" on him and nuclear safety and security standards.
Grossi is expected to hold talks in Moscow and Kyiv next week on the creation of a protection zone around the Zaporizhzhia plant, the watchdog said on Saturday.
Ukrainian Foreign Minister Dmytro Kuleba said on Sunday that Grossi had assured him in a telephone call that the IAEA would spare "no effort to ensure the release of ZNPP director abducted by Russia".
Kuleba also said that Ukraine was ready to facilitate the rotation of IAEA experts at the Zaporizhzhia station. Several IAEA experts have been working at the power station since early September.
"I stressed that Russia must withdraw troops and military equipment from the station," Kuleba said on Twitter.
(Reporting by Michael Shields; additional reporting by Pavel Polityuk in Kyiv; Writing by Michael Schields and Lidia Kelly; Editing by Kirsten Donovan and Sandra Maler)