"I find it impossible, as well as risky, to think up further accommodation structures," said Raggi in a letter sent to Paola Basilone, the prefect of Rome, in which she called for a "moratorium" on further new arrivals.
The mayor cited as reasons for the request the "strong migratory presence" in the capital and "the continued influx of foreign citizens".
According to the most recent figures published by the administration, on January 1st 2016 there were approximately 364,632 foreigners living in Rome, amounting to 12.7 percent of the total population.
This was more or less the same as the previous year, but represented an increase of 6.2 points since the year 2000. And according to the Roman Observatory on Migration, Lazio is the Italian region with the second highest number of migrants, outdone only by Lombardy.
Across Italy as a whole, around 8.3 percent of the population is foreign, according to Istat figures which were also released on Tuesday.
In Rome, around half of the foreign population were from Europe, with Romania the best represented country.
These statistics were replicated on a national level, with European nationals accounting for more than 50 percent of the total foreign population and Romanians making up 23.2 percent of the total.
Beppe Grillo, the leader of the Five Star Movement party to which Raggi belongs, chose Tuesday to publish a blog post about the Rome administration's efforts to dismantle the Roma camps in the capital.
That announcement was made at the end of May, with Raggi labelling the camps "a feeding trough to the mafia", a reference to the Mafia Capitale trial in which previous administrations were accused of collaborating with criminal gangs to profit from funds destined to help those living in the camps.
"Now in Rome, things are changing," Grillo wrote on Tuesday. "Closure of Roma camps, and a census of all abusive areas and tent camps."
The comments came after the Five Star Movement suffered a setback in local elections, with its candidates failing to advance to the second round of voting in any regional capitals or larger cities - including Grillo's hometown of Genoa.
The ruling centre-left Democratic Party also achieved only modest results, with the centre-right performing best in the votes, which were the last time Italians will go to the polls before general elections.