U.K. Says Russian Mercenary Group Aims to Assassinate Ukraine’s President

Wagner emerged from Russia’s covert interventions in eastern Ukraine in 2014, where the Kremlin worked with armed groups funded by politically connected Russian businessmen. Wagner was financed in part by multimillion-dollar catering and construction contracts for the Russian armed forces awarded to companies linked with

Yevgeny Prigozhin,

a former restaurateur, according to European officials.

A representative of Mr. Prigozhin called into question the existence of Wagner Group and said questions about the U.K.’s claim represented “a severe psychosis of Western media,” without commenting on the claim itself. The company couldn’t be reached for comment.

The Wagner Group has already been sanctioned by the European Union, which accuses it of being a proxy force for Russia’s Defense Ministry. The Kremlin has in the past denied any formal connections with the group.

U.K. officials have in recent weeks spoken of their worry about Mr. Zelensky’s safety amid the war in Ukraine and numerous reports of attempts on his life.

The U.K., EU and the U.S. have already imposed sanctions on Mr. Prigozhin. The U.K. has also sanctioned his mother and daughter.

Wagner Group arrived in Syria shortly after Russia entered the conflict on behalf of the Assad regime and conducted support operations such as seizing oil and gas fields and securing other government infrastructure, such as airports.

—Thomas Grove contributed to this article.

Write to Max Colchester at max.colchester@wsj.com