A career diplomat who once was a frontrunner to head UNESCO has been appointed Russia's ambassador to Britain, the Kremlin said Thursday.

Alexander Yakovenko, 56, previously a deputy foreign minister, was mentioned for the London job last fall, but the Kremlin took four months to mull over his candidacy, apparently seeking not to disturb an ongoing “reset” in ties with Britain.

Yakovenko replaces Yury Fedotov, who became director of the United Nations Office on Drugs and Crime in September.

Yakovenko sought the job of UNESCO director-general last fall, but the post was assumed by Bulgarian Irina Bokova in October.

“He is known to be a cautious diplomat who can suppress his emotions. It is important today when there is a need to avoid controversial issues,” Sergei Utkin, analyst at the Moscow-based Institute of World Economy and International Relationships, said by telephone.

Russian-British ties soured after the 2006 poisoning death of Alexander Litvinenko, a former security officer and outspoken Kremlin critic, in London. Russia refused to extradite Britain's main suspect in the case.

But the situation has improved under the current British government. Both countries understand “the need for reset,” Utkin said. “But in both countries there are forces who desire to ruin the reset."