An Irish-born American cardinal was entrusted by Pope Francis to be the camerlengo, the Vatican official who runs the Holy See after the death of one pontiff and before the election of another.

Following the death of Pope Francis, a cardinal from the United States has become acting head of the Vatican until a new pontiff is elected.

Pope Francis, 88, died April 21, the Vatican announced. No cause of death was included in the statement. In February, after a bout with bronchitis, he had been hospitalized in Rome with what Vatican officials called a “complex clinical picture” that included a diagnosis of double pneumonia.

Global tributes are being paid after Pope Francis died of a stroke and heart failure on Easter Monday at Casa Santa Marta, a guesthouse at the Vatican.