Mayor of New York City Bill de Blasio has confirmed that the city is on "increased alert" today following the Brussels attacks.
However he stressed that there was "no specific or credible threat" made against New York, but that the city remained the "number one terrorist target in the United States", so heightened measures were required.
The FBI and New York police are sending detectives to Belgium to assist the investigation because US citizens are among the casualties.
A special NYPD counter-terrorism taskforce has been deployed to certain areas in the New York including the subway system and at locations connected to the Belgian government.
Extra police have also been deployed to tunnels and bridges.
There is a heightened police presence across the city with police officers working double shifts and called in on days off.
The NYPD Deputy Commissioner of Intelligence and Counter-terrorism John Miller said the full resources of the police department had been deployed to secure the city within an hour of receiving notification of the situation in Brussels.
Mr Miller said that the extra police resources deployed included heavy weapons teams, special weapons teams, and the canine unit including dogs trained to detect explosives and other dogs expert in detecting suicide bombers in crowds.
There are significant numbers of extra police at New York's subway stations and airports today.
At subway stations there are increased bag checks at entrances in addition to special machinery which can detect explosive residue.
The NYPD also said it was working with Europol at this time to share information.
