The Italian capital was one of the first of the four cities so far in contention to announce that it would compete. Budapest, Hamburg and Paris are also in the race, while Los Angeles is expected to enter after Boston's embarrassing withdrawal. Toronto is also considering entering.
Giovanni Malago, president of the Italian Olympic Committee (Coni), said the historic Colosseum could be used in the Italian campaign. Rome's mayor, Ignazio Marino, has proposed using the Colosseum for medal ceremonies.
But Malago said the exact role of would only be revealed after the International Olympic Committee deadline for bids closes on September 15th.
Early reports also said an event like archery could be held in St Peter's Square in the Vatican. But Malago ruled this out for religious reasons.
"It would not be right to involve the Vatican in our bid" because of its connection to the Roman Catholic Church, he told a small group of reporters on the sidelines of an International Olympic Committee meeting in Kuala Lumpur.
The Coni president said Rome wanted all religions involved.
"Islamic, Hebrew, Catholic, they will be co-protagonists" in the Italian campaign, Malago commented.
He also ruled out holding a referendum as some other Olympic candidate cities have.
He said other ways would be used to measure "public opinion" but did not give details.
Malago said the bid would be based on Rome, but that football would be held in six cities across the country and that sailing could be in Sardinia, Naples or Venice on the Adriatic. The decision will be made by the International Sailing Federation.
"We want to be compact as we think this is a plus," he commented.
Rome was a candidate for the 2020 Games, but the government abandoned the effort because of the country's economic troubles before the event was awarded to Tokyo.
Canadian Olympic Committee president Marcel Aubut gave backing, meanwhile, for a Toronto campaign for 2024.
"After the enormous success of the Pan-American Games, the time has come for Toronto to go forward," Aubut told AFP.
Several city leaders have called for Toronto to enter and Aubut said he would work on details when he returns to Canada.
Aubut said he did not think that a legislative election on October 19th would stop Prime Minister Stephen Harper, a conservative, from backing Toronto.
"On the contrary, I have the impression that all the parties are open to the idea. It is difficult to go against young people, against sport and against the city of Toronto," said the Olympic official.
Canada has organized only one summer Olympics, in Montreal in 1976.