(CNN) Pope Francis has described two of Russia's ethnic minority groups, the Chechens and Buryats, as some of the "cruelest" troops fighting in Ukraine.
The pontiff was speaking in an interview with a Jesuit magazine, America, which was published on Monday but took place on November 22, according to the outlet.
"The cruelest are perhaps those who are of Russia but are not of the Russian tradition, such as the Chechens, the Buryats and so on," he said. "I speak of a people who are martyred. If you have a martyred people, you have someone who martyrs them."
Chechens are an ethnic group originating from Chechnya in southern Russia. Ramzan Kadyrov, the pro-Kremlin leader of the region, has largely been supportive of the war in Ukraine, and has even reportedly sent his own sons to fight there.
The Buryats are an ethnic group from eastern Siberia, in an area which borders Mongolia.
Russia's Foreign Ministry spokesperson, Maria Zakharova, defended Russia's ethnic makeup on her official Telegram channel.
"We are one family with Buryats, Chechens and other representatives of our multinational and multi-confessional country," she said. "And together we will definitely pray for the Holy See, each in his own way."
In the interview with America, the Pope also addressed the anniversary of the Holodomor, a man-made famine that led to the death of millions of Ukrainians in 1932-33.
The anniversary of the famine, which is widely attributed to the Soviet leader Joseph Stalin, is usually marked on the fourth Saturday of November.
"The genocide that Stalin committed against the Ukrainians [in 1932-33]. I believe it is appropriate to mention it as a historical antecedent of the [present] conflict," the Pope said.
Russia's invasion of Ukraine has also caused tensions between Francis and Patriarch Kirill, the head of the Russian Orthodox Church.
In June, the Pope described the war as Russian "expansionism and imperialism," and in May urged Kirill not to "become Putin's altar boy."
Two planned meetings between officials from the two churches have been canceled since the Russian invasion in February.
The first was due to take place in Jerusalem in April, and the second in Kazakhstan in September.
The leaders of the two churches have only ever met once, in Cuba in 2016, since the Great Schism in the 9th Century.