Turkey’s foreign ministry has lodged a formal protest with the Vatican after Pope Francis referred to the mass murder of Armenians as “the first genocide of the 20th century,” Catholic World News reported.

The Pope alluded briefly to the Armenian Genocide during a June 3 meeting with Armenian Catholic Patriarch Nerses Bedros XIX Tarmouni of Cilicia. Several years earlier, while serving as Archbishop of Buenos Aires, then-Cardinal Jorge Bergoglio described the killing and forced deportation of millions of Armenians as “the gravest crime of Ottoman Turkey against the Armenian people and all of humanity.”