Mayor Bill de Blasio said Monday that the visit by Pope Francis -- "the strongest moral voice on this planet" -- to New York City on Thursday and Friday will be a joyous and historic occasion, and the NYPD and Secret Service are prepared for anything, including the pontiff's spontaneous nature.

He urged the city to brace itself for delays and inconveniences.

"It's going to be a joyous week, it's going to be an exciting week, it's going to be an inspiring week for New Yorkers as we welcome Pope Francis," de Blasio said.

De Blasio at a City Hall news conference presented Staten Island Catholic school students with tickets to see the papal procession Friday through Central Park.

"You will be telling this story to your children and to your grandchildren," he told the schoolkids.

The mayor said he is inspired by the pope's message.

"He's calling for global economic justice, global environment justice ... and to treat all people with compassion and humility," de Blasio said.

Law enforcement officials are prepared for the security challenges of the pontiff's visit with several stops in Manhattan, including a Mass at Madison Square Garden, de Blasio said.

"We are absolutely ready," the mayor said, adding that the law enforcement is also prepared for Pope Francis' tendency to spontaneously reach into crowds and otherwise veer from security protocols.

"Whatever he chooses to do, we will do our very best to accommodate and continue to protect him throughout," he said.

There have been no specific threats to Francis' safety, de Blasio said.