Officials stress there is no credible threat against the United States, but the extra security is being added out of an abundance of caution.
Police are reporting to the French consulate and other locations that have French connections.
Additionally, the MTA has positioned extra officers at Penn Station and Grand Central Terminal. Port Authority police are on heightened alert at all of the agency's bridge, tunnel, rail, World Trade Center and other facilities. Actions include increased patrols and checks of bags, buses, trucks and trains at agency locations. Travelers are reminded to remain vigilant and report any suspicious activities to police or other authorities.
Mayor Bill de Blasio phoned into Eyewitness News to discuss the attacks overseas:
The mayor said New York City is always evaluating its security measures for attacks like the one in Paris.
"The city is on constant alert, and we're working very, very closely with our federal partners - homeland security, FBI, etc. - so we are ready," de Blasio said.
He said the city's actions following the attack are strategic.
"But every time we see an attack like this it's not only sobering, it's a reminder to be prepared, to be vigilant, and to make sure that we're reinforcing in places where there'd be the greatest likelihood of a potential follow-up attack," he said. "That's why we're focused on these French government locations here in New York City."
The NYPD's Strategic Response Group (SRG) will be patrolling key locations.
More on the NYPD's response around New York City:
The SRG is devoted to "advanced disorder control and counter-terrorism protection," responding to world events.
The specially-trained unit of up to 350 officers with heavier gear is assigned to both counter-terrorism patrols and protests at high-risk areas of the city, like Times Square.