Pope Francis has suggested people who choose to have pets over children are acting selfishly.
The Pope's comments came as he was discussing parenthood during a general audience at the Vatican in Rome.
"Today ... we see a form of selfishness," he told the audience. "We see that some people do not want to have a child.
"Sometimes they have one, and that's it, but they have dogs and cats that take the place of children.
"This may make people laugh, but it is a reality."
The practice "is a denial of fatherhood and motherhood and diminishes us, takes away our humanity", he added.
Pope Francis said that people who are unable to have children for biological reasons should consider adoption, urging people "not to be afraid" in embarking on parenthood.
He also spoke of a "demographic winter" - possibly referring to countries with declining birth rates - in which "we see that people do not want to have children, or just one and no more".
It is not the first time Pope Francis has taken aim at people who choose pets over children.
In 2014, he said that having pets instead of children was "another phenomenon of cultural degradation", and that emotional relationships with pets was "easier" than the "complex" relationship between parents and children.
The 85-year-old Pope has been photographed petting animals ranging from dogs to panthers in the past, but he is not thought to have a personal pet.
His 2015 visit to the United States was marked by dog owners dressing their pets in canine papal outfits with the hashtag #popedog on Instagram.
Asked at the time if the Pope was aware of the trend, a Vatican spokeswoman said: "I imagine he has more important things to think about."