Opponents of allowing gay couples to marry on Monday praised Pope Francis' remarks on the family, but the nation's leading LGBT rights advocate says it's encouraged by the Catholic leader's words.

More than 350 people from around the world gather at the Vatican to attend the 3-day conference, titled Humanum.

“It is fitting that you have gathered here in this international colloquium to explore the complementarity of man and woman,” the Pontiff said. “This complementarity is a root of marriage and family.”

“When we speak of complementarity between man and woman in this context, let us not confuse that term with the simplistic idea that all the roles and relations of the two sexes are fixed in a single, static pattern. Complementarity will take many forms as each man and woman brings his or her distinctive contributions to their marriage and to the formation of their children – his or her personal richness, personal charisma. Complementarity becomes a great wealth. It is not just a good thing but it is also beautiful.”

“Family is an anthropological fact – a socially and culturally related fact. We cannot qualify it based on ideological notions or concepts important only at one time in history. We can't think of conservative or progressive notions. Family is a family. It can't be qualified by ideological notions,” he added.

Tony Perkins, president of the Christian conservative Family Research Council (FRC), said he was encouraged by the pope's words.

“Conservatives concerned about where @Pontifex is headed on #marriage will be encouraged by his address today,” Perkins tweeted.

Brian Brown, president of the National Organization for Marriage (NOM), messaged: “'#Marriage is more than Good; it is about beauty.' The beauty of complementarity of male and female.”

“Hold on,” HRC said in a blog post. “Nowhere in the remarks does [Pope Francis] demean or even dismiss committed and loving gay and lesbian couples in any way. He honors straight couples and the children that result from opposite-sex marriages without denigrating LGBT people. In fact, he encourages his audience – which included many anti-LGBT advocates and priests from around the world – to take a more modern view of the family.”