NYPD Commissioner Bill Bratton says his department is operating as though attacks like those in Paris could happen in New York City. 

Bratton said Monday on MSNBC's "Morning Joe" that the NYPD is constantly working to thwart attacks in a city that remains among the world's top terror targets. The NYPD has beefed up security and staffing, including at the French consulate, France's mission to the United Nations and Times Square.

Bratton says the Paris attackers' use of suicide vests is of particular concern, and officers are trying to learn more about the capability and types of arms used in the vests. He says an NYPD team will head to Paris this week to bring back lessons that investigators can use in New York.

Meanwhile on Long Island, police patrols are being increased at shopping malls, sporting events and other large public gatherings. 

Acting Nassau County Police Commissioner Thomas Krumpter said his department works closely with the federal Joint Terrorism Task Force, and although there are no known "credible threats," the department's intelligence unit monitors developments "24 hours a day." 

Krumpter added there were more police at a weekend professional soccer game. Members of the department's Bureau of Special Operations also patrolled shopping malls. Added patrols were also expected at houses of worship.

He did not offer specifics on the numbers of additional patrols, or officers. He said the added patrols were likely through the upcoming holiday shopping season.

New Jersey state police were also on alert, and have increased staffing for a more visible presence. More troopers were seen at the Giants-Patriots game in East Rutherford. Port Authority police are increasing patrols as well ans checking bags, buses, trains and trucks at agency locations.