Russia's Foreign Ministry issued a note of protest to Yerevan after an Armenian delegation visited Bucha earlier in June, Russian state-controlled news agency Russian state-run media outlet TASS reported on June 9.
Bucha, a suburb northwest of Kyiv, was occupied by Russian troops shortly after the full-scale invasion of Ukraine began in February 2022.
After the city was liberated at the end of March 2022, mass graves with civilians were discovered, and thousands of war crimes were documented, making Bucha a symbol of Russian atrocities in Ukraine.
Armenian Ambassador to Ukraine Vladimir Karapetyan and Tigran Ter-Margaryan, the head of the Nor Nork district of Yerevan, met with Bucha Mayor Anatolii Fedoruk on June 2.
"During the meeting, the possibilities of establishing cooperation between the Bucha community and the Nor Nork administrative district of Yerevan were discussed," the Armenian Embassy in Ukraine said on social media.
The Armenian delegation laid "flowers and honored innocently killed residents of Bucha near the memorial complex" and "handed over humanitarian aid in the form of medicines."
"We are proud of the courage of the Ukrainian people and are always ready to support Bucha and other communities affected by hostilities," the Embassy quoted Ter-Margaryan saying.
Russia considers the visit "to be an unfriendly step," Tass said, citing Russia's Foreign Ministry Spokesperson Maria Zakharova.
Zakharova claimed that the protest note was issued "in connection with the transfer of assistance to the needs of the Armed Forces of Ukraine and the unacceptable statements made there against Russia."
Recent months have seen a growing rift between Yerevan and Moscow, exacerbated after Russian "peacekeepers" in Nagorno-Karabakh did not prevent Azerbaijan's armed seizure of the region in September 2023.