The agency confirmed safety advisor Ryan Evans was one of six Reuters employees staying at the Hotel Sapphire in the city of Kramatorsk – which is under Ukrainian control but near the front line – when it was hit.
Ukrainian authorities said the hotel was struck by a Russian missile but Russia has not commented.
The National Police of Ukraine said earlier that the body of a 40-year-old British man was recovered from the rubble of a hotel at 18:35 local time on Sunday after a 19-hour search.
Writing on Telegram, Ukrainian president Volodymyr Zelensky sent his condolences to the family and friends of the man killed.
The Ukrainian General Prosecutor’s Office wrote in a statement that the hotel had likely been hit with a short-range Iskander-M missile.
Kramatorsk is only about 12 miles from Russian-occupied parts of Ukraine, and has come under regular attacks, with civilians killed, including celebrated Ukrainian writer Victoria Amelina.
The Russian military has been making slow but steady advances in the east in recent months, with Ukraine’s recent offensive into Russia seen as an attempt to draw troops away from the eastern front line.