NEW YORK - When revelers pack Times Square for the annual New Year's Eve celebration Monday night, police will observe a tradition of their own: giving them lots of company.

Each year, the New York Police Department assigns thousands of extra patrols - in ways seen and unseen - to the festivities to control the crowd and watch for signs of trouble. Hundreds of thousands of people from all over the world are expected to pack into the midtown Manhattan streets to see the crystal ball drop and ring in 2013.

"We think it's the safest place in the world on New Year's Eve," Police Commissioner Raymond Kelly told the Associated Press ahead of the holiday.

Security in Times Square has become an obsession for the NYPD in the post-9/11 world, especially since the attempted car bombing there in the summer of 2010. More recently, details emerged in a different case in Florida indicating that one suspect considered Times Square as a potential target.

"Times Square is an iconic location that draws a significant number of people every day," Kelly said. "New Year's Eve is the apex of that, so we have to plan accordingly."

Kelly stressed that there are no specific terror threats related to a celebration televised across the globe. But believing that the so-called Crossroads of the World is always in the crosshairs of would-be terrorists, the nation's largest police department has turned securing the event into a science.

Hotels are a particular concern. The department has worked closely with managers, urging them to guard against anyone who might seek to check into a guest room and use it for a sniper or other type of attack.

"We ask them to monitor people coming into the hotels very closely," Kelly said.

In terms of crowd control, police noticed last year that revelers starting flocking to Times Square earlier in the day to hear rehearsals of performers scheduled for various telecasts. "At one o'clock in the afternoon, there was a significant crowd," Kelly said. "It was really packed with people."

So this year, the department will adjust by posting more officers on the streets before nightfall, the commissioner said.

Along with the army of additional uniformed officers, police will use barriers to prevent overcrowding and for checkpoints to inspect vehicles, enforce a ban on alcohol, and check handbags. Visitors will see bomb-sniffing dogs and heavily armed counterterrorism teams. Rooftop patrols and NYPD helicopters will keep an eye on the crowd as well.

Other plainclothes officers are assigned to blend into the crowd.