Pope Francis has paid tribute to the generations of Japanese Christians who for more than two centuries retained their traditions despite efforts by authorities to eradicate the faith, in some cases by torture and execution.

Meeting with 16 Japanese Catholic bishops at the Vatican on Friday, the pope said Japan's "hidden Christians" were a model of resilience in the face of oppression.

"Though small in number and daily facing persecution, these believers were able to preserve the faith," he said, attributing this in part to the Christians' "sincere commitment to the welfare of the community." The comments were made in a written statement delivered to the bishops.