NEW YORK -- With thousands of pilgrims expected to visit Rome for the Jubilee year, the Italian government invited police from all over the world to assist with security.
After the attacks in Paris, Italian officials say they are not taking any chances.
So for the first time, a team of New York City police officers are in their uniforms working overseas.
It's a first for the NYPD and the Italian police, but this joint international security operation at the Vatican is a sign of the times.
"In light of recent events in Europe and in the United States, we continue to learn and we continue to adapt," said Sgt. Stephen Cafasso, of the NYPD Intelligence Bureau.
Police from New York, Spain, and Poland are in Rome, assisting with security for the Catholic Church's year-long Jubilee of Mercy.
It's only the 27th time in the history of the church that there has been a holy year, and this year Italian officials say there will be increased police patrols for a good reason.
"Islamic State group," said Nicolo D'Angelo, the Chief of Rome police.
He explained that they cannot underestimate or ignore the ongoing threat posed by ISIS, especially following the recent attacks in Paris.
Authorities say they deployed thousands of officers and soldiers from across Italy and asked for help from around the world.
"It's been a great opportunity to share ideas, exchange different ways of how we do things, but also to see, you know although we do certain things different, it's also kind of gives us a good feeling to know that a lot of what we do is, very similar," said Insp. Joseph Gallucci, of the NYPD Intelligence Bureau.
For security reasons, Italian authorities are not revealing the exact number officers taking part in this operation, but ABC News is told there will be visible police presence at the Vatican and across the city at all times.