Mayor Bill de Blasio may have thought he was getting out of town at the right time when he went to Rome this week, just as the fight between City Hall and Uber was reaching a fever pitch, but he soon learned that he could not escape the Uber debate, even at the Vatican. NY1's Grace Rauh filed the following report.

When mayors from around the world gathered at the Vatican this week, the official purpose was to talk about climate change. But at times, the conversation veered to another topic: the car service Uber. It is upending the traditional taxi industry around the globe.

"I think it's clear that as a corporation, as a multi-billion-dollar corporation, Uber thinks it can dictate to government," de Blasio said.

That was de Blasio, not at City Hall but at the Vatican, where he was able to commiserate with other mayors about his problems with the car service. In Paris, taxi drivers held violent demonstrations against Uber earlier this summer.

"We have talked about this," Anne Hidalgo, the mayor of Paris, said through an interpreter. "I support him. We have the same problem in Paris, even though it is not my direct jurisdiction. I support him in what he's doing."

At the time, de Blasio was pushing a cap on Uber cars so the city could study the industry. He has since backed off of the cap but is going ahead with study.

Other mayors, like Ed Lee of San Francisco, are much more upbeat about car service companies like Uber. Its headquarters are in his city.

"We've had trouble with taxis in our city because they didn't get everywhere that people really wanted," Lee said. "And so now, they are turning the corner with their own technology, and that's been kind of forced on them with this competition."

California Governor Jerry Brown warned de Blasio to avoid doing anything rash.

"We have a very convenient technology that a lot of people really like," Brown said. "So all I would say is, study it very carefully."

The taxi wars, though, are not playing out in all big cities. The service does exist in Rome, but it is not that popular, at least not yet.

De Blasio did not take any taxis while in Rome. He rode in his own van, and he walked.