VATICAN CITY — Now trending on Twitter: Pope Benedict XVI.

On Monday, the Vatican announced that the 85-year-old pontiff would begin posting messages on Twitter next week under the handle @pontifex, a term for the pope that means “bridge builder” in Latin. Within hours, he had more than 250,000 followers.

Benedict is expected to send his first post at a general audience at the Vatican on Dec. 12 — a response to questions about matters of the faith that he is now accepting via the hashtag #askpontifex, officials said.

The Vatican acknowledged that it had chosen the @pontifex handle not only because of its meaning but also because many other handles had been taken.

The move is aimed at drawing in the Roman Catholic Church’s 1.2 billion followers, especially young people. “The pope’s presence on Twitter can be seen as the ‘tip of the iceberg’ that is the church’s presence in the world of new media,” the Vatican said in a statement.