In the Italian capital the soldiers will help guard Jewish schools, the city’s synagogue and diplomatic residences.
The measures, announced after a meeting of military and security officials, will be implemented until at least June.
Authorities consider Rome particularly sensitive because it is home to the Vatican.
In the past, Islamic militant websites have posted vague threats against Pope Francis and the Roman Catholic Church.
The news comes amid rising fears of attacks by Islamic extremists in Italy after the beheadings of 21 Egyptian Christians by terror group IS.
The atrocity, shown in a gruesome video released on Sunday, happened on the Libyan shore of the Mediterranean Sea which is a short boat ride from Italy.
Pope Francis earlier today labelled the film a “barbaric assassination” of innocents who he said were killed for their faith.
Entitled “A Message Signed With Blood To The Nation Of The Cross”, the IS video shows Coptic Christians handcuffed and dressed in orange jumpsuits.
In the sickening five-minute clip their blood can later be seen filling the waters of the Mediterranean Sea.
Speaking today, he said: “Their only words were: ‘Jesus, help me!’ They were killed simply for the fact that they were Christians.
“The blood of our Christian brothers and sisters is a testimony which cries out to be heard.
“It makes no difference whether they be Catholics, Orthodox, Copts or Protestants. They are Christians.”
There is rising in concern in Italy about IS establishing a presence on the shores of the Mediterranean just a few hundred miles from them.
Authorities fear that terrorists could covertly try to sneak into Italy with the thousands of migrants who are making their way across the Mediterranean.
Prior to the latest IS video emerging, Italy’s defense minister Roberta Pinotti told the Il Messaggero newspaper: “The risk is imminent.
“We cannot wait any longer. Italy has national-defence needs and cannot have a caliphate ruling across the shores from us.”
—Courtesy of Pamela Gellar