Pope Francis has spoken of his desire to see gay people integrated rather than marginalised.

The Pope said he could not judge people who were gay but stressed that the Church's official position on homosexual acts as being sinful remained unchanged.

He was speaking to reporters on the papal plane as he flew back from Brazil, where he made his first international trip as pontiff to participate in World Youth Day.

"If a person is gay and seeks God and has good will, who am I to judge them?" he said. "They should not be marginalised."

He added later that rather than being marginalised because of their homosexuality, they "must be integrated into society".

The comments mark a departure from the stricter interpretation of his predecessor, Pope Benedict XVI, who moved to block gay men from becoming priests and was outspoken in his opposition to gay marriage.

Despite his sympathetic tone towards homosexuals, Pope Francis was firm that he would not tolerate any lobbying by gay people.

"The problem is not having this orientation," he said. "We must be brothers. The problem is lobbying by this orientation, or lobbies of greedy people, political lobbies, Masonic lobbies, so many lobbies. This is the worse problem."

And despite expressing his support for women in the Church, he was clear that they should not be permitted to the priesthood.

"We cannot limit the role of women in the Church to altar girls or the president of a charity, there must be more," he said.

"But with regards to the ordination of women, the Church has spoken and says no."

He added: "That door is closed."