London (CNN) Holiday gatherings of large crowds always require extra security, but even more protective measures are being put in place for New Year's Eve festivities in European capitals and the US this year.

The moves follow truck-ramming attacks in Berlin and Nice, France; as well as bomb attacks in Istanbul, Turkey, and stabbings and shootings in Germany, France, the Netherlands, Belgium, the UK and Denmark.

Berlin

Up to 4,600 extra police officers will be deployed around the German capital, more than double the number of additional personnel who were deployed for New Year's Eve last year. Police armed with machine guns will be on patrol throughout the city, traffic checkpoints will be set up and bag checks will be conducted. Police will cordon off the Brandenberg Gate, a focal point of celebrations where one million revelers are expected to gather.

Twelve people were killed and at least 48 more injured when a truck plowed through an open-air Christmas market in Berlin on the evening of December 19.

Anis Amri, a 24-year-old Tunisian who pledged allegiance to ISIS in a video before the attack, is accused of hijacking the steel-filled tractor-trailer, killing the Polish driver and plowing through the crowded market. He fled Berlin after the attack and was killed in a shootout with Italian police in Milan on December 23.

Paris

The City of Light has mobilized 10,300 police, gendarmes, military and fire personnel for New Year's Eve. According to Paris police chief Michel Cadot, 1,700 police officers will be deployed on the French capital's Champs-Elysées, where bag and coat checks will be conducted at 24 checkpoints around the area. In addition, 230 private agents have also been hired by the mayor's office, a first for the city.

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In response to the truck attack in Berlin earlier this month and one in Nice on July 14 -- in which Mohamed Lahouaiej Bouhlel drove a 20-ton truck into crowds on the Promenade des Anglais seafront during a fireworks celebration, killing 85 and injuring more than 200 -- concrete studs are being added as a preventative measure around the perimeter of the Champs-Elysées. Officials have canceled the fireworks launch from the Eiffel Tower, replacing it with a light and pyrotechnic show.

London

Around 3,000 officers will be on duty across central London on New Year's Eve, both within and outside the ticketed areas where events are taking place. Armed officers regularly patrol the London Underground system and these patrols will be extended through Sunday, as was the case last New Year's Eve.

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British Transport Police spokesman told CNN that the decision to extend patrols was taken many months ago, before the Berlin attack, and is not in response to any specific intelligence or threat. Across the country, police officers will be deployed at train and tube stations.

Rome

More than 1,000 uniformed and plain clothes officers will patrol the Italian capital over New Year's Eve and New Year's Day. The officers will be mainly deployed around the Circus Maximus and along bridges over the Tiber river. Vehicles will be barred from the bridges and barriers will be places around gathering areas.

Heightened security is in place for New Year's Eve festivities in Rome.

In a statement, Rome police said the measures "are designed to achieve the maximum security without generating excessive barriers or concerns." Police have also launched a social network campaign with the hashtag: #dacciunamano, or "give us a hand," which will allow revelers "to share with the authorities any notice of strange or alarming situations.. Police say there is no specific information on a threat to the city.

In Naples, an extra 800 security agents will be patrolling the streets, officials said.

New York

The New Year's Eve celebration in the Big Apple will for the first time have 65 sand trucks around the area of Times Square, New York Police Commissioner James O'Neill said at a briefing Thursday. Chief of Departments Carlos Gomez said the vehicles will be placed in strategic locations.

Preparations are under way in Times Square ahead of the New Year's Eve celebration.

The enhanced security measures are not based on any new credible threat or intelligence, but are purely a precaution due to the continued calls from ISIS for its sympathizers to carry out truck-style attacks, a law enforcement source previously told CNN.

O'Neill said that "at this time we have no direct concerns related to terrorism, to Times Square specifically, or New Year's Eve in general" adding that the NYPD monitors and assesses threats 24 hours a day and confers regularly with law enforcement.

There is no specific or credible threat to NYC, but if you see something, say something -- alert an officer, call 911 or 888-NYC-SAFE. #NYE pic.twitter.com/068UpnzOmj — NYPD NEWS (@NYPDnews) December 30, 2016

Mayor Bill de Blasio said on New Year's Eve, people will see "extraordinary" assets deployed from the NYPD, including the Critical Response Command and Strategic Response Group, and there is a lot "you will not see."

As many as 7,000 NYPD officers will work the event, Gomez said. There will be highly visible heavy weapons teams in Times Square and other areas outside the city, he added.

Explosive detecting canines will be deployed in Times Square and through the subway system, Gomez said. Police details have also been increased at Coney Island and Central Park -- which will also be ringed by sand trucks and blocker cars, NYPD Assistant Chief Terry Monahan said.