Pope Francis has officially recognised Archbishop Oscar Romero of San Salvador as a martyr, clearing the way for him to be named a saint.

Romero was killed on March 24, 1980, as he celebrated mass in a hospital in San Salvador. His death came the day after he had publicly called for soldiers to lay down their guns and end government repression.

Originally chosen as a conservative figure, he became increasingly horrified by the actions of the Salvadoran government during the country's vicious civil war and spoke out against poverty, social injustice, assassinations and torture.

The announcement was made today by the Congregation for the Causes of Saints, which is responsible for investigating the lives of candidates to ensure that they are suitable. It had previously pronounced in his favour, leaving Pope Francis, an admirer of Romero, to rubber-stamp the decision.

Francis had told journalists on his flight home from South Korea in August that Romero was a "man of God" and that there were no impediments to the declaration that he had died for his faith.

Romero's sainthood cause was opened in 1993 but stalled over political questions: Pope Benedict XVI told reporters in 2007 that the archbishop was "certainly a great witness of the faith" who "merits beatification, I do not doubt." But he said some groups had complicated the cause by trying to co-opt the archbishop as a political figure.