How Law Enforcement Is Preparing for New Year's Eve Celebrations

— -- U.S. law enforcement agencies are ramping up their resources and deploying extra personnel for New Year's Eve celebrations.

FBI and Department of Homeland Security officials said they are not aware of any specific, credible threat to the homeland; however, there has been a surge of suspicious activity reports and a litany of potential threats coming in from across the globe, prompting safety concerns.

Counter-terrorism officials, local police departments and federal agencies are working through the weekend to reassure the public and thwart any potential attack.

After the deadly shooting in San Bernardino earlier this month, officials increased security personnel for the Rose Bowl.

“You have to hope for the best and plan for the worst,” said Mark Selby, the deputy special-agent-in-charge for ICE’s Homeland Security Investigations in Los Angeles, who is coordinating federal security partners for the event.

More than a year ago, the annual game held in Pasadena, California, was designated a top-level security event by DHS, which allowed for “unprecedented” federal resources, such as air support, a dozen bomb-sniffing dogs, and license-plate readers to collect basic information on vehicles heading in and out of the area.

Lone-wolf attackers remain one of the biggest concerns, although there is no information of a planned attack, said Selby.

While some European cities cancelled plans for New Year’s Eve celebrations because of security threats, U.S. cities are opting for a heightened police presence and enhanced technology to keep revelers safe.

In Los Angeles, police officials say their officers will be highly visible, as they always are during such events. An LAPD spokesman said his agency will be reminding officers and citizens alike to “be on alert” and notify authorities of anything suspicious.

In New York City, the NYPD is deploying more than 5,000 officers to Times Square, where more than 1 million people are expected to watch the ball drop in person.

In addition to the extra officers, the NYPD will be using helicopters, boats, cameras, radiation detectors and other counter-terrorism measures to maintain safety.

“The threat picture has changed because of ISIS,” said Commissioner Bill Bratton during an on-camera briefing.

For New Year's in the nation's capital, police are executing an "enhanced deployment strategy" across the city and dispatching additional personnel to "nightlife areas," according to a department spokesman.

ABC News' Aaron Katersky contributed reporting.