New York police will use sand-filled trucks, radiation detectors, bomb-sniffing dogs and heavily armed officers on Thursday to defend the 90th Macy's Thanksgiving Day Parade, which Islamic State has encouraged its followers to attack, according to Reuters.

Officials expect 3.5 million people to converge on the 4 km parade route in Manhattan for the annual, nationally televised ritual that initiates the holiday shopping season with giant balloons shaped like cartoon characters.

The 82 sand trucks from the Sanitation Department will be used to counter a threat by Islamic State, also known as ISIS, ISIL or Daesh, which has called the parade an "excellent target."

The group has encouraged readers of its online magazine Rumiyah to use motor vehicles to kill and injure people, similar to the way a Tunisian-born assailant killed more than 80 people at a Bastille Day celebration in Nice, France.

The sand trucks weigh 16 tons (14.5 metric tons) and twice that when filled with sand, making them difficult to move even if rammed by large vehicles.

Islamic State, which controls swathes of Iraq and Syria and seeks to inspire attacks by others abroad, claimed responsibility for the July 14 attack in Nice.

Police have also used the sand trucks to protect nearby Trump Tower, the home and campaign headquarters of President-elect Donald Trump.

This year police will ban vehicle traffic from crossing the parade route, unlike in past years when a few cross streets were open, requiring the trucks and 114 smaller blocker cars.