ROME — Pope Francis has formally ratified the martyrdom of the Salvadoran archbishop Óscar Romero, who was shot to death at the altar as he was saying Mass in 1980 in an act of “hatred for the faith,” the Vatican said on Tuesday.

The step opens the way for Archbishop Romero to be beatified — a process that had been blocked under Francis’s predecessors, Vatican watchers say, because of the archbishop’s leftist political stances.

The archbishop, a man of the poor who often denounced social disparities, violence and repression in his own country and throughout Latin America, remains much beloved among Catholics in the region, and Francis, the first Latin American pope, has been outspoken in his appreciation of the archbishop.

At the beginning of the civil war in El Salvador, Archbishop Romero angered the country’s right-wing military government by calling on soldiers to disobey orders to murder political opponents. He also wrote a letter to President Jimmy Carter pleading with him to cut off American military aid to El Salvador. The archbishop was killed by a right-wing death squad.