New York City Mayor Bill de Blasio on Thursday joined with Police Commissioner Jim O'Neill to announce a tougher security plan for the city on New Year's Eve, although the mayor said there were no credible and specific threats at this time.

Each year, an estimated 2 million people gather in New York City's Times Square to watch the ball drop. The New York Police Department has a series of annual protocols it will deploy for the event, but after two terror attacks since Halloween, security will be even more stringent.

New Year's Eve attendees in Times Square will be screened twice upon entrance to the square, which will be patrolled by weapons teams and bomb-sniffing dogs, according to Terry Monahan, the NYPD's chief of patrol. Parking garages will be closed and sealed, and there will be teams working with security staff at all hotels near the square.

There will be additional details assigned to monitor Central Park and Coney Island.

"There will be much the public will see and much the public will not see," O'Neill said. "The bottom line is, we will keep you safe."

Despite the heightened security measures, de Blasio emphasized there is no known threat to the city for New Year's Eve. He encouraged New Yorkers to continue to be aware.

"There are no credible and specific threats against NYC at this time, and no credible and specific threats to Times Square at this time," de Blasio said during the conference. "Help each other be safe. If you see something, make sure a police officer knows about it."

Cities around the country are deploying heightened security this year in advance of New Year's Eve celebrations.