Pope Francis admitted that he knew of the "close friendship" between St. John Paul II and a female philosopher named Anna Teresa Tymieniecka, saying that there was nothing wrong with this since even popes need "healthy, holy friendships" with women.

The pope made the statement to reporters onboard the papal jet taking him back to the Vatican from Mexico on Wednesday, Newsmax reported.

Officials at Poland's National Library who have read the letters exchanged between St. John Paul II and Tymieniecka say they indicate that the latter might have been in love with John Paul, but that the pope kept the relationship on a friendly and intellectual level.

Pope Francis said he knew of their friendship, adding that any man who is unable to have a good friendship with a woman "is missing something."

The pope said he himself values the advice of women since they "look at things in a different way" than men do.

"A friendship with a woman is not a sin, it's a friendship," he said.

Pope Francis made it clear though that "a romantic relationship with a woman who is not your wife" is a sin.

He said the pope is also a man with "a heart that can have a healthy, holy friendship with a woman."

Pope Francis noted that St. John Paul II was not the only religious leader who had close friendships with women, citing the close ties between St. Francis and St. Clare of Assisi, and the one between John of the Cross and Teresa of Avila.

The pope admitted though that the Catholic Church still has not thought of a way to show how much it values women.

"We have not understood the good that a woman can do for the life of a priest and of the church," he said.

Early in his papacy, the pontiff said the church needs more women in governance positions. But after three years as the head of the Roman Catholic Church, Pope Francis has appointed very few women to high-level Vatican positions.

He has also remained firm in his opposition to the ordination of female priests.