Pope Francis appeared to have confirmed his critics' deepest concern, telling journalists on Sunday that the apostolic exhortation on family he issued recently did open up "new concrete possibilities" for Catholics who divorce and remarry without first obtaining annulments.

The Pope also commented on his brief meeting on Saturday morning with U.S. Democratic presidential hopeful Bernie Sanders, saying it was not meant to make any kind of political statement, the National Catholic Reporter reports.

Meeting with journalists aboard the papal plane on his way back to Rome after a one-day visit to Lesbos, Greece, the Pope was asked if he had made specific changes to the church's pastoral practice for remarried Catholics.

"Are there new concrete possibilities that did not exist before the publication of the exhortation, or no?" one journalist asked.

"I can say yes. Period," Pope Francis replied.

He then told the journalists to check the presentation given by Austrian Cardinal Christoph Schönborn at the Vatican on April 8, the day the new exhortation, titled Amoris Laetitia ("The Joy of Love"), was released.

In his presentation that day, Schönborn said the document had made some "organic development" of the church's pastoral practice for divorced and remarried couples.

In Amoris Laetitia, Pope Francis dealt with many issues, saying that Catholic bishops and priests can no longer make blanket moral determinations about so-called "irregular" situations such as divorce and remarriage.

"It ... can no longer simply be said that all those in any 'irregular' situation are living in a state of mortal sin and are deprived of sanctifying grace," the document states.

Critics say that the Pope's apostolic exhortation raises the possibility that adulterous sexual acts might in some cases be justified.

One of the critics, a group called Voice of the Family, said attempts to undermine Catholic teaching on matters relating to human life, marriage and the family will only weaken the Church's witness to the truths of the natural and supernatural order, threatening the well-being of the family, especially its weakest and most vulnerable members, LifeSite News reports.

Meanwhile, Pope Francis also told reporters that Sanders simply came to greet him on Saturday morning.

"This morning, when I left, Senator Sanders was there," said Francis. "He knew that I would go at that hour and had the kindness to greet me."

"Nothing more," said the pope. "If someone thinks that saying hello is to get mixed into politics, I recommend they see a psychiatrist."